William Clark, 77, who left the Strathclyde force after 30 years service with the rank of detective chief inspector was confronted in court today with statements bearing his name.
Mr Clark told the trial that when he arrived at the lane off Ardgowan Street, Greenock on the morning of June 2 1986 Elaine had been covered with a blanket to protect her naked body from curious onlookers.
The jury have heard that Mr Clark said much the same when questioned in 2009 - after his retirement.
Then, in June 2012 another detective visited Mr Clark at his home to be told: “There is confusion about the blanket in the last statement.”
Mr Clark continued: “I am certain that when I arrived at the crime scene there was no blanket over the body of Elaine Doyle.”
At the High Court in Edinburgh today, puzzled Mr Clark told advocate depute John Scullion, prosecuting: “I never said that. I know my signature is there but that totally contradicts everything that happened.”
Mr Clark also disputed the suggestion there had been a “heated discussion” between himself and other senior detectives.
He said he knew that the placing of a blanket over the body would make forensic examination “pointless” but kept his opinion to himself.
The trial also heard that towards the end of 1986 Mr Clark produced a 21-page report, up-dating prosecutors on how the investigation had been conducted up to that point.
There was no mention of the blanket question in the report - “an oversight” claimed Mr Clark today.
The report did give some indication of the massive police operation which began with the discovery of 16-year-old Elaine.
Police believed they were looking for a sex killer, possibly a dog walker who had used a dog lead to strangle the teenager.
The opening games of the Mexico City World Cup had brought men onto the streets to exercise their pets later than usual, said Mr Clark.
Door to door inquiries took in 22 major streets. Taxi drivers who might have seen something were questioned. Police tried to trace every male over the age of twelve who had been out after midnight.
By the time the 1986 report was written, almost 50 officers had logged more than 46,000 hours working on the inquiry.
John Docherty, 49, now of Hunters’ Quay, Holiday Village, Dunoon, denies murder. He claims 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.
The charge alleges that on June 2 1986 in a lane near Elaine Doyle’s home in Ardgowan Street, Greenock, he seized her by the hair, struck her on the head and either removed or compelled her to remove her clothing.
The charge goes on to allege that Docherty forced Elaine to the ground, pushed her face into the ground, sat or knelt on the teenager then placed a ligature round her neck and strangled her.
Docherty also denies stealing a handbag from Ardgowan Street on the same date.
He further denies a charge of attacking another woman, Linda Hargie, on various occasions between 1990 and 1995 at an address in Anne Street, Greenock by seizing her and pushing her and punching her on the head.
The trial continues.