Levi Bellfield is one of two people who could have leaked his confession to the murders of Lin and Megan Russell, a solicitor claims.
Paul Bacon, who represents the man currently jailed for the murders, says he, Bellfield and an unnamed person are the only three he is aware knew the statement existed.
Mr Bacon said: “I am very concerned that it was leaked.”
He said he had not even told his client Michael Stone, serving three life sentences for killing Lin, 45, and her six-year-old daughter in Chillenden, Kent, in 1996. Mr Bacon would not say how he got the document.
He said he had planned to give it to the Criminal Cases Review Commission before telling the Russell family.
Serial killer Bellfield has a history of lying, retracting statements and playing mind games with victims’ families. After the 2002 murder of Milly Dowler, 13, Bellfield first admitted to then denied the killing.
He has previously denied murdering Lin and Megan. Mr Bacon said results of DNA tests on a bootlace found at the Russell murder scene should arrive within months.
The result is expected in a report by the CCRC, who have said they will carefully analyse any evidence given.
