Leigh Sabine abandoned her 5 kids to start a new life. She kept an even darker secret for 40 years.

Lee Sabine was known by her neighbours as the mysterious oddball living next door, in the small village of Beddau in Wales. Some called her a fantasist, others said she was a liar, either way she left an impression on everyone she encountered.

But Lee Sabine had a secret; a secret she had been guarding for decades.

Kept inside the confines of her home was a decaying corpse, concealed in 40 layers of plastic wrapping. After the body was discovered in 2015, Sabine quickly became a suspect and the case became one of the most peculiar murder mysteries in Welsh history.

The police had a prime suspect but they were presented with two problems: the suspect was dead and the victim's identity was unknown.

This investigation is revisited in the three-part documentary The Body Next Door, which is streaming on Stan. As someone who watches a lot of true crime documentaries, I can confidently say that this is one of the most enthralling ones I've ever seen.

It might start out as a run-of-the-mill murder investigation but the three-part series quickly evolves into so much more.

The true story that inspired Stan documentary The Body Next Door.

In November 2015, a month after Leigh Ann Sabine died of brain cancer, one of her friends Rhian Lee found a body in the village's communal garden — but at first, she thought it was a 'medical skeleton' that Leigh spoke about often.

"That morning I went over to my friend Michelle's [James] for a cuppa and we thought, for a laugh, we'd play a prank," Lee told The Sun.

"We knew about the medical skeleton wrapped up like a big package under the potting table in the garden and so we thought we'd bring it in, put it on the settee and give a knock to the neighbour to come down to see, as a joke."

The friends started to cut through the wrapped plastic layers before a thick liquid started seeping out. Inside the packing was a body that had been wrapped 41 times in plastic supermarket bags.

Police would arrive at the scene to discover that the wrapping had created a mummifying effect while slowing down the decomposition.

The skeleton would later be identified as John Sabine who died as a result of blunt-force trauma. Police believed he was murdered by his wife Leigh Ann before her death in October 2015.

John and Leigh Sabine. Image: Stan.

Due to the way the body was preserved, police had trouble pinpointing a time of death for John but they estimated it was as far back as 1997. Neighbours had said they hadn't seen John outside of the house in decades, with Leigh claiming her husband left her for another woman years before.

Leigh had deceived those around her into thinking that John's body was a skeleton she kept for years. "Leigh was always talking about a medical skeleton," Leigh's carer Lynne Williams said in the documentary.

"On numerous occasions she wanted it moved… we were sitting around the table having a cup of tea and she mentioned the skeleton again and I said 'well I hope it's not a bleeding real one' and she went 'you never know Lynne'."There had not been a murder in Beddau for 20 years, which meant the case quickly made national headlines.

The murder investigation was only part of the documentary The Body Next Door, as what was uncovered about Leigh Sabine quickly dredged up decades of hidden family secrets.

John and Leigh Sabine may have ended their lives in Wales, but they began their journey on the other side of the world in Wellington in New Zealand where they brought up five young children.

But Leigh had other ideas for her life.

In 1969, the couple abandoned their five children, aged between two and 11, in a nursery in Auckland before selling their home and taking up new identities in Sydney, Australia where Leigh had hoped to become a cabaret singer.

Meanwhile, their five kids were brought up in foster care, an experience they have since said was traumatic and abusive.

Then 15 years later, the Sabines returned to New Zealand in 1984 to reunite with their children. At first, the kids moved into their home, despite the children being well into adulthood by then, but eventually daughters Jane and Lee-Ann reported their parents to the authorities and the local media.

In New Zealand media, the Sabines made the headlines as the "child dumping" couple which led the New Zealand minister for social welfare to order an investigation. At the same time, Leigh told the newspapers that she wasn't the kids' mother.

By 1984, the couple fled New Zealand again, this time relocating to Wales to the small town where Leigh grew up.

The NZ Herald spoke to one of her children, Jane Sabine, following the discovery of her father's corpse in 2015. She spoke about how her upbringing with foster parents led to abuse and a loss of identity.

"I feel disconnected. I am the age I am now, yet I am still that little girl with the need to know. That [need for a] sense of belonging," the then 50-year-old said.

"I used to get mad at people that said they were adopted because I used to think, 'At least your parents gave a damn. They loved you enough to say, 'Hey, I can't look after you. I want you to have the best life you can' and they signed a piece of paper [so they could] be with a family that nurtured them and loved them regardless.

"Our parents didn't even care enough to do that."

In 2015, Sabine's son Steven told Wales Online that he knew his mother was capable of killing his dad.

Steven Sabine speaks out in The Body Next Door. Image: Stan.

"If anyone was going to do it, she was going to do it. My father was actually a good man, a soft-hearted man. But she was a conniving bitch. She controlled him but he loved her to pieces," he said.

"I could never forgive him for what he did but I still believe he was manipulated and he fell in love with an evil woman. That was his biggest crime."

An inquest into John Sabine's murder found that he was unlawfully killed, most likely by his late wife, Leigh, with some suggesting that an ornamental frog inflicted his fatal head injuries.

The hearing found that during a 1997 phone conversation between Leigh and her friend Valerie Chalkley, she had admitted to killing her husband but Valerie didn't believe her.

"The problem with [Leigh] was you never knew if she was telling the truth or not," Chalkley said.

By the time his body was found, John had not been seen in public in 18 years.

"Precisely what happened and the circumstances will sadly never totally be known," the coroner Andrew Barkley said.

In the documentary, a neighbour recalled that Leigh, an aspiring cabaret star, once boasted "after I die, I will be famous."

Sadly for all her victims, Leigh Sabine's wish came true.

The Body Next Door is streaming on Stan. 

Feature image: Stan.