An Afghan migrant who raped and drowned an EU official's daughter in Germany had lied that he was an unaccompanied minor and was probably about 25, dental checks have revealed.

Hussein Khavari, who claimed to be 17, admitted raping and strangling Maria Ladenburger after ambushing her as she cycled home from a party in Freiberg at 3am one day last October.

The 19-year-old medical student, whose father is a senior legal adviser to the European Commission in Brussels, was then drowned in a river in a case that shocked Germany.

Ladenburger had volunteered to help out migrants in various shelters and homes before her death although it was not known if she had met the man who killed her before.

Her body was found the day after her murder in the River Dreisam.

A strand of Khavari's hair was found on her body and tests revealed he had been jailed for 10 years in Greece for the attempted murder of a woman he threw off a cliff in Corfu in May 2013.

The Times reported that Greek authorities had let him out of prison on licence after 18 months in a scheme to relieve pressure on overcrowded cells.

German police did not know about his jail term and Khavari was let into the country as a registered asylum seeker.

Khavari, who had been drinking and taking drugs on the night of the murder, had testified that he accidentally came across Ladenburger who shouted out as she fell from her bicycle.

The Daily Mail reported that he said he pressed her mouth shut then choked her with a scarf and put her unconscious into the water.

He stated that "when I saw how pretty she was, I wanted to have sex with her" but claimed he was too drunk to follow through.

Khavari originally claimed to be 17 but said he did not know exactly, and that he was no older than 19 years old.

After discovering the tooth that was removed eight-months before the murder dental expert Ursula Wittwer-Backofen revealed her analysis of his upper right canine tooth, on Tuesday (7 November).

Wittwer-Backofen said his true age is with 99.7% probability between 22.05 and 29.55 years, but that she was certain he was 25, reported the Mail.

The new evidence from his tooth now means he facing sentencing next year as an adult.