The man convicted of murdering Cardiff prostitute Lynette White has told a jury he killed her alone.
Jeffrey Gafoor, 46, who was jailed for life in 2003 for Ms White's 1988 murder, is a prosecution witness in a Swansea Crown Court trial.
Five innocent men were charged with her murder, and he said he felt "terrible" about what they had been through.
Eight ex-police officers deny conspiracy to pervert the course of justice. Two other people deny perjury.
Three men, who became known as the Cardiff Three, were wrongly convicted of the docklands murder.
The prosecution claim that the former South Wales Police officers manufactured evidence that led to the convictions of Ms White's boyfriend and pimp Stephen Miller, Yusef Abdullahi - who has since died - and Tony Paris.
'Miscarriage of justice'
The men, who became known as the Cardiff Three, were convicted in 1990 of the murder but released from jail two years later by the Court of Appeal.
Taking to the stand in Swansea, Gafoor was asked by the prosecution if he had pleaded guilty in 2003 to Ms White's murder.
"Yes I did," he replied.
He denied knowing any of the three men who were convicted of the murder in 1990.
"I now feel that it was a miscarriage of justice," he said. "Their problems stemmed from my actions and I feel terrible about it.
"I know that they did not have anything to do with it and that they were completely innocent because I was the one who killed Lynette White.
"All the injuries she had she received from me. There was no cover-up of the killing."
"Grasped for knife"
Gafoor, who worked as a security guard, described stabbing the 20-year-old in the flat where her body was found after an argument over money.
"I met Lynette White for her services as a prostitute but I changed my mind and asked for my money back," he said.
"We argued and I grasped for a knife to threaten her to get my money back.
"We both had the knife. In the course of an argument I stabbed her and she was killed.
"I remember stabbing but it is all a bit vague. I mean fuzzy. I don't want to say dreamlike but it is a lot like that.
"It seemed to go on a long time. I was shouting and she was shouting back at me."
He was asked if anyone else was in the flat at the time and he replied: "No, I was the only person in the flat.
"When I last saw her she was in the flat face down on the floor."
The court has heard that after her death seven months of police investigation failed to get any result so officers allegedly began to "fit up" the innocent men for the murder.
They invented a fictional scenario which was "almost entirely a fabrication and was largely the product of the imagination," the court has heard.
Questioned by William Coker QC, the barrister representing former Chief Insp Graham Mouncher, Gafoor denied being pressured into taking full and sole responsibility for the crime.
He agreed that after he had been jailed for life - but before he had been told the minimum number of years he would serve before being released on parole - he was interviewed by detectives probing the original police investigation.
In 2004 he again met police who by then had turned the interview into a statement and asked him to check it and sign, if he agreed it was all true and accurate, the court heard.
Gafoor was reluctant to sign because the declaration included the statement that he was willing to appear in court if the investigation led to a prosecution.
Mr Coker asked him if he could remember asking a police officer what could be the consequences of not signing, and was told: "It could affect your release date."
To that, Gafoor allegedly replied: "So it's technically blackmail."
Mr Gafoor said he could not, now, remember those words.
Mr Coker also said there was a connection between Gafoor and the men originally jailed for her murder.
The court was told Gafoor's aunt, Marjory Gafoor, had been a prostitute working close to the murder scene at the time.
Mr Coker said her son, Tony Dickman, had a girlfriend who was the best friend of Leanne Vilday, who led police to the body.
He added that Gafoor had previously been represented in court by a barrister and solicitor who also represented men who had been earlier tried for the murder.
The former officers are accused of conspiracy to pervert the course of justice by agreeing to "mould, manipulate, influence and fabricate evidence".
The accused all deny the charges.