France's oldest female detainee has gone on trial for murder at a court in Versailles, in a cold case centring on a dismembered body found 31 years ago.

Marie-Thérèse Garcia, 79, is charged with the kidnap and murder of her former sister-in-law Corinne Di Dio.

Di Dio went missing in June 1995 when she was 37. Days later, a metal trunk bound with a metal chain was discovered floating in the River Seine to the west of Paris.

Inside was the dismembered corpse of a woman – without head and hands. Only in 1997 was the body identified as Di Dio's, while the missing body parts have never been found.

Garcia early on came under suspicion, but twice the case was closed for lack of evidence.

Recently, though, DNA technology gave police a breakthrough. Two hairs found inside the metal trunk were found to belong either to the defendant or to another woman in her matrilineal descent.

In 2023, Garcia was put in prison to await trial. Repeated pleas for conditional release on grounds of age and ill health have been turned down.

Dubbed Ma Dalton by the French press – after the redoubtable grandmother of the Lucky Luke comic strip – Garcia protests her innocence, telling Le Parisien newspaper recently that the case against her was "built on sand".

"No-one knows what happened. And in law if you don't know, you can't convict," she said.

Her lawyer Najwa El Haïté argued: "The way [Di Dio] was killed – they were the methods of the underworld, of organised crime. No head, no hands – that's not the method of a Marie-Thérèse, a woman with no criminal record."

The complicating factor is that Garcia and Di Dio were both very much connected to the criminal underworld.

Back in the 1980s, Di Dio was the lover of Antonio Marquez-Gomez, a Spanish national known to police for his links to the drugs trade.

They were parents of a child, Romain, now aged 41, who was often looked after by Garcia. She in turn had a relationship with Antonio's brother, Francisco.

According to reports, their wider circle had included two well-known brothers from the criminal underworld: Jean-Jacques and Philippe Maurice. Philippe gained fame when he was the last person to be condemned to death in France, before being granted clemency by then-President François Mitterrand.

During the three-week trial, the prosecution will argue that Garcia lured Di Dio to her home near Rambouillet, south-west of Paris, where in the sitting-room she was stabbed to death and dismembered.

The motive prosecutors will try to establish was a pact between Garcia and Marquez-Gomez to get the boy Romain, then aged 10, away from his mother. The accused also allegedly bore a grudge against the victim because she had engaged in an affair with Francisco.

Marquez-Gomez is also accused of murder in the case, but he is believed to be living in Colombia and is untraceable.

Romain told Le Parisien last week that, a few days after his mother's disappearance, Garcia entrusted him to his father, who was by then living in Madrid with a wife and children.

"I'm 10 years old, and suddenly I'm in Spain with a father I barely know and a family whose language I do not understand. That moment is not just a memory, it's a scar," he said.

Other evidence expected to be brought up in the trial is the testimony of the 79-year-old's daughter Nancy, who in 2004 told police she had heard her mother discussing murder on the telephone a short time before Di Dio's disappearance.

Police were also alerted by a strange coincidence surrounding the disappearance of a young couple in 2022, one of whom was the great-niece of the defendant.

When police tapped Garcia's telephone, she was heard saying that if she caught the culprits she would "cut them up and put the pieces in a suitcase".

Described in the French press as a headstrong woman who is generous to friends but implacable to her enemies, Garcia says the case against her is circumstantial.

"The hairs they found were brown, but back then everyone knows I had black hair," she told Le Parisien.

"And if I'd wanted to remove every woman who Francisco slept with, there wouldn't be many women left in the world. There's no proof against me. No clue. No motive. It's all built on sand."