10 Of Australia’s Strangest Unsolved Mysteries

12 min read

Australia might not have a long history, but we do have something of a mysterious one.

In fact, we have more than our fair share of strange happenings in this country, but people rarely know about them. So, we thought we’d share some of our favourite unsolved Australian mysteries, to see if the Stay at Home Mum readers has any good theories as to what might have happened in each of these cases.

You never know, you could be the one who solves them!

More Reading:

men abuse | Stay at Home

1. Disappearance Of Rhianna Barreau

  • Location: South Australia
  • Date: October 1992

In October of 1992, 12-year-old Rhianna Barreau was walking to her local mall in South Australia to buy a card for a pen pal in America. She couldn’t catch the bus because the drivers were on strike, so her mum agreed she could walk, saying goodbye to her as she went off to work. Witnesses saw Rhianna walking along Highway Drive just before noon.

It would be the last anyone would see of her.

When Rhianna’s mum arrived home in the afternoon, she found the card on the dining room table, a record on the floor, and the TV playing loud in an empty room. She called for her daughter, but nobody replied. She searched, but there was nothing. Frantic, she called the police.

Now, almost 25 years later, there are still no answers for Rhianna’s mum as to what happened to her daughter. In 2015, a $1 million reward was offered for any credible information, but nobody came forward. Rhianna’s mum still lives in the same house, hoping that one day, her daughter might return, or she’ll get some answers as to what happened.

2. The Case Of Mr. Cruel

  • Location: Melbourne
  • Date: Late 80’s and early 90’s

In the late 1980s and early 1990s, an unknown serial paedophile and rapist had the people of Melbourne terrified. He was known by the media as Mr. Cruel, and with good reason. In August of 1987, he broke into a Lower Plenty family home, armed, and tied up both parents and their son. An 11-year-old girl was attacked.

Then in 1988, he broke into a home in Ringwood, kidnapped 10-year-old Sharon Wills, and held her for 18 hours before releasing her. He struck again in 1990, breaking into a Canterbury home and abducting 13-year-old Nicola Lynas, whom he held and abused for 50 hours before releasing her.

It was in 1991 that he struck his killing blow, although some experts have expressed doubt that Mr. Cruel was behind the killing, although it certainly matches his M.O. It was April of 1991. A man armed with a knife abducted 13-year-old Karmein Chan. A year later, her body was found with three gunshot wounds. Her murder remains unsolved.

In working to solve the case of Mr. Cruel, police have searched some 30,000 homes based on the kidnapped girls’ descriptions, and interviewed around 27,000 suspects. There is currently a $300,000 reward available for information that leads to an arrest, but police have admitted that some vital evidence, which may provide DNA proof, has gone missing.

3. Serial Killings At Tynong North

  • Location: West Gippsland, Victoria
  • Date: 1980’s

A man dumping animal remains in Tynong North in December of 1980 sees across some suspicious bones. To him, they look human and he called the police. They uncovered the remains of three women, and two years later, a fourth victim is found in the same area.

The fourth woman was Narumol Stephenson, who disappeared just a month before the remains were first found. Other victims were 14-year-old Catherine Headland and 73-year-old Bertha Miller, both of whom disappeared in August of 1980, some 18 days apart, and 18-year-old Ann Marie Sargent, who went missing in October of the same year.

Over the next three decades, police name several suspects, and even link the Tynong North serial killings to two more murders in Frankston, but none have been solved. Despite an in-depth investigation by teams of police officers, they don’t even know whether the killer is a single person, or a team of murderers.

4. Disappearance of Frederick Valentich

  • Location: Bass Straight
  • Date: October 1978

Frederick Valentich, a 20-year-old pilot in training, was on a 235km training flight over the Bass Strait in October of 1978. His aircraft was a light plane, a Cessna 182L, and Valentich had around 150 total hours of flying time. His intention was to have a career in aviation, but admittedly, he had a poor past achievement record having failed twice the five commercial licence examination subjects, and having been rejected from the RAAF.

On this flight however, something was wrong. Valentich radioed into Melbourne air traffic control and reported that he was being followed by an aircraft, around 1000ft (300m) above him. He reported that the aircraft was large, unknown to him, and moving at high speed. Not long after, he radioed in to say it was now orbiting above him, and that it had a shiny metal surface and a green light. The controller asked Valentich to identify the aircraft, and he sent his last communication: “It isn’t an aircraft”. There was the sound of metal scraping, and Valentich was never heard from again.

A sea and air search was launched looking for the wayward pilot or any sign of his plane, but despite spanning over 1,000 square miles, nothing was found. Search efforts ceased four days later. Many theories have been suggested as to why Valentich reported what he did, some say that he likely saw a UFO, and others suggest he was confused and simply made an error. Looks like we’ll never know.

5. Lasseter’s Lost Reef

Likely one of the most well-known and enduring of Austria’s unsolved mysteries, Lasseter’s Reef has entertained and eluded decades of searchers. It started in 1929 (and again in 1930) when Harold Bell Lasseter made a number of conflicting claims that in 1897, he had found a large amount of gold in the desert. Lasseter claimed that he had found a very rich vein of gold on his travels, something he described as a “vast gold-bearing reef in Central Australia”.

The last photograph of Lasseter, taken on his departure to find his "lost" reef on September 15, 1930. Photo: Supplied by Chris Clark
The last photograph of Lasseter, taken on his departure to find his “lost” reef on September 15, 1930. Photo from

According to Lasseter, he had been a young man of 17 when he rode by horse from Queensland to the goldfields of WA. On the way, he came across the reef of gold, somewhere between the border of the NT and WA. He believed he was some 1,100km west of Alice Springs, in line with Kalgoorlie. Lasseter got into some kind of trouble and was rescued by an Afghan camel driver.

Over the next several decades, Lasseter tried on several occasions to raise funds and find the gold reef, but he was never successful. When the gold rush finished in 1930, during the Great Depression, Lasseter was able to secure £50,000 for an expedition to the reef. Their search party included motorised transport, an aircraft, and several experienced bushmen, but they never found it.

The myth continues today, and it has become a prominent Australian folk tale. Nobody knows if Lasseter was actually helming the truth, and we’ll likely never know the truth.

6. Shadowy ‘Family Murders’

The Family was a name given to a mysterious group of men who were thought to be behind the kidnapping, drugging, torture and sexual abuse of young men and teenagers in Adelaide in the 1970s and 1980s. Five young men were murdered in the state between 1979 and 1983, and many of the police suspects had high-profile occupations, which led to the conspiracy. Some experts have suggested these murders were not the only ones, and were merely a part of a larger string of kidnappings and sexual assaults of boys and young men at the time.

The victims were 16-year-old Alan Barnes, 25-year-old Neil Muir, 14-year-old Peter Stogneff, 18-year-old Mark Langley, and 15-year-old Richard Kelvin. Bodies were found in each case, and although little could be determined from Peter Stogneff’s murder, the other four all died of massive blood loss from anal injuries.

Peter Stogneff |
Peter Stogneff |

Police believed that as many as 12 people were involved in the killings, including a number of high-profile individuals. Despite this, four of the five murders remain unsolved, with only one person jailed in the murder of Richard Kelvin, a man named Bevan Spencer von Einem. Einem was also the last person to be seen with Neil Muir after his abduction, and he is currently serving life in prison. A $1 million reward has been offered for any information that leads to a conviction in the other cases.

7. The Man On The Crucifix

Fisherman Mark Peterson was out on the Hawkesbury River in August of 1994 when he felt a strong tug on his fishing net. It was a lovely day, and Mark was convinced he had snagged a decent haul. Unfortunately, what he pulled up from the water was not fish at all, but a heavy piece of steel in the shape of a crucifix. Attached to it were the remains of a person.

Peterson rang the police in shock and they took possession of the remains and the crucifix. Forensic pathologists found that the remains were of a human male, aged between 21 and 41, and that the body had been intentionally arranged on the crucifix. The entirety of the body was wrapped in plastic, including the head, and there was wire wrapped around the head and torso of the victim.

Unfortunately, due to the erosion of fingerprints the man couldn’t be identified. Called the Rack Man by the media, he remains a mystery to this day, although the case hasn’t been closed by police. Some believe he might be a drug dealer who went missing in 1993, but that is yet to be proven.

64e3c34a33fcaef1930fd400fa8845d8 | Stay at Home reconstructed face of ‘rack man’.Source:News Corp Australia

8. Missing Sarah MacDiarmid

Sarah MacDiarmid was on a train home in July of 1990 after playing tennis with friends. She was travelling from East Melbourne back to Kananook, where she had left her vehicle, when she disappeared without a trace. Her friends left the train at Bonbeach, leaving Sarah alone. She was last seen getting off the train at Kananook station and heading to her car in the carpark at 10:20pm.

Police investigating the disappearance found bloodstains on the ground beside her 1978 Honda Civic, which had been left at the station’s car park. They also noted there were drag marks that led into the bushes. There they found a cigarette lighter belonging to Sarah. Those were the only clues.

A massive air, sea and land search was conducted over three weeks, with more than 250 police personnel involved, but nothing was uncovered. Later, appeals for information uncovered two witnesses who reported they had heard a woman at the station yell: “Give me back my keys”. A $1 million dollar reward is current for any information that solves the case.

article 0 1E06814400000578 | Stay at Home | Sarah MacDiarmid, 23, vanished from a railway station near Frankston, Victoria in 1990 and her body was never found.

9. Vanishing Cessna 210

In August of 1981, a Cessna 210 was registered to travel from Proserpine to Sydney. Four passengers are on board, along with the 52-year-old pilot Michael Hutchins. The plane, numbered VH-MDX, sent out a radio transmission to air traffic control as they neared the community of Taree. According to the pilot, bad weather was ahead, and he needed permission to fly in a restricted area to avoid the storm. Then, the pilot changed his mind, staying on his original course.

Not long after that, an integral part of the plane fails, leaving the pilot with no sense of direction and no horizon simulator or heading indicator. Along with strong winds and ice, as well as plane malfunction, there was extreme turbulence. The last response from Hutchins was terrified and cut short: “Five thousand-“. The plane was never seen again.

A number of exhaustive land and air searches were conducted involving police, rescuers and volunteers, but no trace of the aircraft or the men was found. Exactly what happened on board, and what happened to the plane, remain a mystery to this day.

10. The Somerton Man

The Somerton Man is probably one of the most internationally renowned of Australia’s unsolved mysteries. Sometimes referred to as the Tamam Shud case, it involves the discovery of a man’s body on Somerton beach in the morning of December 1, 1948. The case is referred to as such because, some months after the body was found, police uncovered a scrap of paper in the man’s pocket on which was printed: tamám shud. The phrase means “ended” or “finished” in Persian.

Police were unable to identify the man, although his autopsy suggested that he had not died of natural causes but had in fact been poisoned and possibly left at the beach, instead of having died there. Clues on his body seemed to lead to more questions, and it didn’t get any easier when his suitcase was discovered 6 weeks after his body at a train station. The scrap of paper in his pocket came from a rare New Zealand edition of a book of poems, which police tracked down (someone had stashed it in the rear footwell of a car). Inside, they found indentations of other writing, which they believe to be a code or encryption.

The case of the Somerton Man is considered to be one of Australia’s most profound mysteries, and has been since it was first uncovered. Years later, there is no consensus as to who the man was, how he really died, how he came to be at Somerton beach, or where he might have come from. A local woman named Jessica Thomson was linked to the case but continued to claim she did not know the dead man. Some think he might have been a spy, but the truth is, we’ll never know.

What other unsolved Australian mysteries are you aware of?

10 Of Australia’s Strangest Unsolved Mysteries Pinnable

Avatar photo
About Author

Oceana Setaysha

Senior Writer A passionate writer since her early school days, Oceana has graduated from writing nonsense stories to crafting engaging content for...Read Morean online audience. She enjoys the flexibility to write about topics from lifestyle, to travel, to family. Although not currently fulfilling the job of parent, her eight nieces and nephews keep her, and her reluctant partner, practiced and on their toes. Oceana holds a Bachelor of Arts with a major in Writing and Indonesian, and has used her interest in languages to create a career online. She's also the resident blonde at, where she shares her, slightly dented, wisdom on photography, relationships, travel, and the quirks of a creative lifestyle. Read Less

Ask a Question

Close sidebar