Lynette White case: 'Corrupt detectives ruined lives'
"Corrupt" detectives ruined the lives of families in their haste to solve the Lynette White murder, a court heard.
Helen Nying, who went to school with Miss White, said police had bullied her into signing false statements and she had suffered ever since.
Three men were wrongly convicted of the 1988 Cardiff murder before being freed on appeal.
Eight ex-police officers deny perverting the course of justice in a trial at Swansea Crown Court.
Ms Nying agreed she had signed statements saying that one of the men wrongly convicted, Tony Paris, kept a knife in his pocket and that he had told her he knew who had murdered Miss White, a prostitute.
She told the court on Wednesday that neither statement was true, but she had been bullied by police officers who had said they would "nail those men and, if I didn't do what they said, they would nail me as well".
She said she could hardly read or write but still signed the statements.
Ms Nying, who now lived in England and had been unable to return openly to Cardiff for more than 20 years, said she had suffered for her actions.
"They just wanted to put people away for the murder instead of doing their jobs properly," she said.
"All they wanted to do was solve the case instantly, at the click of the fingers. In the process they took other people down with them.
"They made me part of the corruption. I can't go back to Cardiff. I have not seen my real dad for 20 years because of those people.
"I have become a victim of the corruption of the South Wales Police. I hate them. I was forced to make those statements. They destroyed the Paris family. They caused so many heartaches.
"The police have hurt me and many, many others in the process."
She said the statements that appeared to incriminate Mr Paris had been the words of police officers and not her own.
Ms Nying, who for a short time worked as a prostitute in Cardiff, said it was true Mr Paris had carried a knife, but it had been nothing more fearsome than a tiny penknife.
Miss White was stabbed more than 50 times in the early hours of 14 February, 1988 inside the Cardiff flat where she used to entertain clients.
Three of the Cardiff Five - Stephen Miller, Yusef Abdullahi and Mr Paris - were later wrongly convicted of the murder and spent four years in custody. Cousins Ronnie and John Actie were acquitted.
The Court of Appeal quashed the convictions in 1992.
In 2003, DNA led police to Jeffrey Gafoor, who admitted murder and was jailed for life. He said he had acted alone.
The trial continues.