A 33-year-old UK man has been jailed for life after admitting the kidnap, rape and murder of a teenager he met on the Facebook social networking site, Reuters reported today.

Convicted sex offender Peter Chapman had cultivated his victim, Ashleigh Hall, 17, by pretending to be a student.

Chapman was told by Judge Peter Fox he would serve a minimum of 35 years in prison, the Press Association reported.

The body of the childcare student was found dumped in a farmer's field near Sedgefield, County Durham, last October.

Hall, from Darlington, had been strangled.

Prosecutor Graham Reeds told Tesside Crown Court that Chapman had posed as a fictitious 19-year-old boy called "Peter Cartwright" on Facebook to befriend the college student, the Reuters report said.

After becoming her Facebook friend and chatting on other social networking sites he arranged to meet her on the evening of Octber 25 last year.

Knowing she was expecting to meet a teenage boy and not a 33-year-old, Chapman led her to believe that "Peter Cartwright's father" would pick her up.

"The defendant used this alter-ego to entice 17-year-old Ashleigh Hall into meeting him," Reeds said.

"When she met him on October 25 last year, he kidnapped, raped and murdered her."

Chapman has been the subject of several sexual assault investigations, beginning when he was 15. In 1996, then 19, he was sentenced to seven years imprisonment for raping two prostitutes at knifepoint. He was released in 2001.