By . Mail Foreign Service . PUBLISHED: . 15:50 EST, 16 January 2013 . | . UPDATED: . 15:56 EST, 16 January 2013 . A convicted rapist is thought to have murdered a British student 23 years ago, a court has been told. Thierry Villetard has been named in French court documents as a suspect for the killing of 20-year-old Joanna Parrish, although he has not yet been placed under formal investigation. The 46-year-old lorry driver comes from the French town of Auxerre, where languages student Miss Parrish was working as an English teacher when she died in May 1990. Unsolved: Twenty three years after Miss Parrish's death, convicted rapist Thierry Villetard has been named in French court documents as a suspect, although he has not yet been placed under formal investigation . An angler found her naked body floating in a river a few miles from Auxerre. She had been raped and strangled. The murder investigation was reopened last year after witnesses – including a former girlfriend of Villetard from 1990 – came forward with what was described as ‘compelling evidence’. The girlfriend claimed Villetard returned home one evening in May 1990 with scratches on his arms and a denim bag similar to the one Miss Parrish was carrying on the evening she disappeared. Other witnesses have told police in Auxerre, which is in Burgundy between Paris and Lyon, that he boasted of killing two women. He is said to have dumped one of the bodies in a river near Auxerre and the other at a motorway rest area. Victim: Joanna Parrish was 20-years-old when she was murdered in 1990 while working as an English teacher in the French town of Auxerre . Villetard, who is described as a ‘habitual sexual attacker’ and is serving an eight-year sentence for rape, is now on trial in Montpellier in southern France accused of  raping the 15-year-old daughter of another girlfriend. In court yesterday he said he ‘remembered nothing’ about the alleged sex attack on the teenager. A prosecutor asked the judge to impose a 17-year-jail sentence on him. The court has been told that Villetard is also suspected of killing Miss Parrish in 1990 and another woman whose body was found beside a motorway in Provence in southern France in 1997. It is understood that a judge in . Paris heading the cold case investigation into Miss Parrish’s murder . will interview Villetard once the trial in Montpellier is concluded. The . Leeds University student, who came from Newnham on Severn in . Gloucestershire, had arranged to meet a man who had answered her advert . for English lessons. She was engaged and was hoping to . make some money for her wedding. Her body was found the next day. Miss . Parrish’s parents, Roger and Pauline, have never given up the struggle . to bring their daughter’s killer to justice. They have long been . critical of the French investigation. Journalists . and police were allowed to contaminate the crime scene so detectives . were left with few clues. Vital DNA evidence was lost, files went . missing and leads were not followed up properly. Until now the main suspect has been French serial killer Michel Fourniret, but he has never been tried. Fourniret . was nicknamed ‘the Beast of the Ardennes’ after he lured seven girls, . aged 12 to 21, to remote spots before strangling, shooting or stabbing . them.  He was jailed for life in 2008 for their murder. His wife, . Monique Olivier, is also in prison for life for complicity. Fourniret . was placed under investigation for Miss Parrish’s murder after his wife . told police that he had killed an English girl while he was living near . Auxerre. It later emerged that Olivier’s statement had been made under duress, with a prosecutor slapping her during an interrogation. French judges wound up the Parrish investigation two years ago through lack of evidence against Fourniret and Olivier.
Joanna Parrish, 20, was raped and murdered in 1990 while working as an English teacher in the French town of Auxerre . Thierry Villetard, a convicted rapist, has been named as a suspect in French court documents .