The Welsh singer has always maintained that the death of Samantha Novak, 25 years ago, was not an accident or suicide. Ms Novak, 21, was found face-down in the River Avon, near the Clifton Suspension Bridge in Bristol.
Shortly after Ms Novak's death, a coroner said it appeared she tumbled off the riverbank after a night out with friends, and there did not appear to be any suspicious circumstances.
But yesterday Avon and Somerset Police revealed that the family of Penny Beale, a victim of killer Michael Moffat, had written to detectives with a new lead.
Ms Beale's mother said the convicted killer claimed to be "involved in the murder" of Ms Novak.
Detective Chief Inspector Mike Carter, the head of Avon and Somerset major crime review team, said:
"There was nothing from the coroner's report to suggest it was murder, rather than suicide. However, this information is obviously additional, so we are making fresh inquiries."
Moffat, 47, originally from Edinburgh, was jailed for 11 years for battering to death Ms Beale, his girlfriend, in Hastings, East Sussex, in 2001.
It is understood that Moffat boasted of being in a relationship with Ms Novak when she died in 1985.