THE father of World's End murder victim Helen Scott has spoken out over a "false" alibi given to Angus Sinclair seven years before the brutal killing of his daughter and her friend Christine Eadie.

Morain Scott, 84, of Edinburgh, said yesterday that the killer, jailed for 37 years on Friday for the double murder of the teenagers 37 years ago, could have been stopped in his tracks in 1970.

A retired senior police officer believes Sinclair was responsible for up to six more murders, including the killing of Helen Kane, 25, a mother of three whose was found in Holyrood Park on May 23, 1970, two years after Sinclair was freed after his first murder.

He had served just over seven years for killing his seven-year-old neighbour Catherine Reehill in Glasgow, a crime he committed when he was 16.

Retired Detective Superintendent Allan Jones, of then Lothian and Borders Police, said that after Ms Kane's body was found Sinclair was questioned and he was given an alibi by "someone very close to him".

Mr Scott, who gave evidence at the High Court in Livingston, said yesterday he believed Sinclair could have been stopped earlier.

He said: "It is unbelievable that someone knowing his record would give him a wrong alibi.

"I would be astounded if they were close to him and never knew what he was like."

Mr Jones said Sinclair was living in Hill Place in Edinburgh, not far from Holyrood Park, when Ms Kane's body was found. She had been abducted and killed on her way home from work.

He said Sinclair was questioned about the killing, denied it, was provided with the alibi which is now thought to have been false and soon after that left Edinburgh for Glasgow.