The missing Sandrine Jourdan, who “disappeared from the face of the earth”, was murdered, according to her family, who received mysterious anonymous letters after her disappearance.

The family of a missing mother is tormented by anonymous letters sent six months after her disappearance.

When 38-year-old Sandrine Jourdan mysteriously disappeared from the small town of Caboolture, Queensland, in 2012, police quickly ruled her disappearance a suicide.

However, his family believes something much more sinister is at play after receiving mysterious letters sent by an unknown person.

The mother of three’s loved ones also reveal how her Facebook account was hacked

The new evidence, revealed on 60 Minutes Australia’s Under Investigation with Liz Hayes, casts strong doubt on the police theory that Sandrine took her own life.

Speaking to the show, her sister Christine Day said: “It’s actually quite scary considering this was sent to where the children lived at the time.” Who does that especially six months after his mother disappeared?

The letters, which were sent to Sandrine’s ex-partner and father of her children, were signed by Rosetta Bunton, a person who does not appear to exist.

Clinical psychologist Tamara Cavenett studied the letters and revealed that they continually imply that Sandrine was promiscuous.

The mother was called a “man-eater” and it was claimed that she “jumped from one man to another” in the cruel notes.

They also contained personal details that only a few people would know, leading the family to believe that the writer was someone close to the family.

Worryingly, in the days before her disappearance, Sandrine told some people that she was receiving threats and wrote in her diary that she feared for her life.

Her daughter Nakita Bulla said her mother was afraid before she disappeared and that “that has been completely overlooked.”

“They made her sound like she was paranoid, but she’s disappeared off the face of the planet,” he said.

Tamara added: “Throughout his diaries he made several comments that he feared someone was hacking into his computer.”

The program asked private investigators to do a forensic analysis of the mother’s laptop, where they found “highly sophisticated encryption software,” technology commonly used by intelligence agencies.

Meanwhile, a second computer belonging to Sandrine also raised the alarm after previously being used to visit a human trafficking website.

Elsewhere on the show, Christine revealed that someone they don’t know has taken over her sister’s account and that her passwords have been changed.

“Their Facebook has been hacked, someone has changed the passwords, access codes and everything, we can no longer access it,” he said.

‘Why weren’t all these red flags examined? I shouldn’t have to keep track of what evidence was turned over to the police or not, but that’s what we’ve had since day one. It makes me angry, it’s still very painful.”

Nakita added: “I am 23 years old and I have had to put the dots together myself about what happened to my mother and it is not my responsibility or my role to do so, it is the responsibility of the police.”

“I feel like she’s been murdered. There’s someone out there who’s gotten away with it, it’s not fair and it’s not right. It’s disturbing, exhausting and sometimes it makes me paranoid that it’s so easy for people to get away with it.

“For me, closure is finding my mother’s body, or just finding out what happened, having a funeral and being able to say goodbye.”

The Queensland coroner’s office has decided to reopen its investigation into Sandrine’s disappearance.

Sandrine had been at a friend’s property in Caboolture, just north of Brisbane, when she disappeared from her driveway on Friday, July 13, 2012, leaving only her jacket on a fence post.

Sandrine’s family knew she suffered from bouts of depression, but said they were closely monitoring her mental health and that two weeks before her disappearance she had completed a healing course.

Police also appeared to have dismissed witness accounts, including Jan Martin, who lives near the property where Sandrine was last seen, claiming she heard three gunshots on the day she disappeared.

“I was in the front yard, near the front door, and all of a sudden I heard ‘bang, bang, bang,'” he said.