A murder trial has heard how Colin McIntyre allegedly "confessed" to being at the scene - just yards from Elaine's Greenock home - with a group of other boys.
Mr McIntyre has said a terrified Elaine, then 16, had begun to struggle when her clothes were taken off and she was surrounded.
Another youth put a length of string round her neck and pulled it tight.
But, giving evidence at the High Court in Edinburgh earlier, Mr McIntyre, 44, claimed none of the account of events in June 1986 was true.
He was giving evidence at the trial of John Docherty, who denies murdering Elaine.
Mr McIntyre claimed he had been threatened by murder hunt detectives, who then wrote the supposed statement themselves.
Michael Langford-Johnston, 64, who retired from Strathclyde Police in 2001 after 32 years service, denied that Mr McIntyre had been bullied.
He told how Mr McIntyre, then also 16, was collected from his part-time job at Greenock's Shamrock Club.
He was questioned and, mid-way through the interview, cautioned when he began to make comments inconsistent with his previous alibi details.
Mr Langford-Johnston told advocate depute John Scullion, prosecuting, that he did not remember exactly what Mr McIntyre had said to lead to a caution that he was not obliged to say any more.
The remarks had been made during "general conversation". He told Mr Scullion he was not aware that Mr McIntyre had made allegations of bullying and threats of violence.
"I certainly didn't threaten," said the former detective, then with Strath-clyde's serious crime squad.
Meanwhile, football fan Daniel Middleton, 49, told police he was watching the World Cup clash between France and Canada around the time the teenager is thought to have been strangled.
He told the court, he was able to tell the officers the colours of the team strips - then admitted he only had a black-and-white television.
The trial heard that on Sunday, June 1, 1986, Mr Middleton had been for a drink in the town centre then walked home after seeing his girlfriend to her bus.
If he arrived home after a goal by French player Papin, he could have been in the area where jeweller's assis-tant Elaine was walking back to her home in Ardgowan Street, at about the same time, Donald Findlay QC, defending, pointed out.
Docherty, 49, of Hunters' Quay Holiday Village, Dunoon, denies murder and says that at the time he is alleged to have stripped and strangled Elaine he was with his parents - who are no longer alive - at their home in Anne Street.
Docherty has also lodged a so-called special defence of incrimination claimed the culprit might be among a list of 41 names taken from files of the police investigation into the murder.
Mr Middleton and Mr McIntyre are on the list.
The trial continues.