Video: Interview with Detective Superintendent David Swindle from Strathclyde Police.
Serial killer Peter Tobin subjected a woman to a horrific sex attack in Glasgow in the 1960s, it has been revealed.
The woman met Tobin in the city's Barrowland Ballroom in 1968 - the year the murders known as the Bible John killings began.
The 63-year-old has already been convicted of the murders of Polish student Angelika Kluk, 15-year-old Vicky Hamilton and Essex teenager Dinah McNicol.
The latest revelation will add fuel to speculation that Tobin was Bible John - the man said to have murdered three women who had been dancing at the Barrowland Ballroom.
Police praised the woman for coming forward. Her identity has not been released, but in an interview with the BBC's Crimewatch, to be broadcast on Monday, she said that at first: "He was very nice to me - laughing and joking ... just an everyday guy."
However, the following night, they met again in the Driftwood bar, on the city's Argyle Street, and he spiked her drink. "I don't remember leaving the pub," the woman said. "The next thing I remember is I woke up and I was fighting for my life."
The woman suffered a violent sexual assault until Tobin was disturbed by a couple living nearby. She went to the police, but he was never caught. She only made the link between her attacker and Tobin after seeing a picture of him - taken in 1973 - in a booklet published by a newspaper.
Detective Superintendent David Swindle, of Strathclyde Police, heads up Operation Anagram - which was set up to analyse Tobin's life and try to identify any other victims. He said the woman's ordeal was "absolutely horrendous".
Mr Swindle told STV News: "This indicates that he was committing serious crime in the 1960s. This is a very significant development. I've got to commend the woman for coming forward."
The detective refused to link Tobin to the Bible John murders. It is possible more than one man was involved in the killings.
"With the type of person Peter Tobin was, we may never know what he has done," said Mr Swindle. "At this time, we're not in a position to say what crimes Peter Tobin did, or did not do.
"I would hope as a result of that that we don't get dragged into speculation, but we end up getting good information that can help us populate the timeline and let us decide what crimes Peter Tobin may have committed."