Police questioned serial killer Levi Bellfield yesterday in a bid to find the grave of an alleged victim.
They visited him in prison in the hope that he could lead them to the body of Elizabeth Chau, who disappeared in 1999.
Bellfield, who is serving a life sentence for three murders, confessed to killing her in March this year.
It is the second time officers investigating the disappearance of 19-year-old Elizabeth in Ealing, west London, have questioned Bellfield.
He is said to have repeated his claims that the Thames Valley University student’s body was buried in a nature reserve near Kempton Park racecourse in Surrey.
A source said: “The police are taking it very seriously.
“The signed confession contains details that only the murderer would know.
“Bellfield cooperated and reiterated that he kidnapped and killed her.
“He drew maps, but it’s a big area.
“One of the things they’re weighing is whether they can get a video link and get him to lead them to the location or even let him out of jail.”
“The case is unsolved and Elizabeth disappeared in an area close to where Bellfield carried out other attacks, so it clearly fits his profile.”
Bellfield, 55, is serving a life sentence for the murders of Milly Dowler, 13, Marsha McDonnell, 19, and Amelie Delagrange, 22.
His lawyer said he was cooperating “fully” and that “the questioning is mainly about the whereabouts of the body.”
The Met Police are taking Bellfield’s claims “very seriously”.