ALISON Lewis, a prime suspect during the hunt for the murderer of Mandy Power and her family, led a secret double life of which Stephen, her police inspector husband, was totally unaware.

The secret - a passionate lesbian affair with Mrs Power - was ultimately to destroy her family, break up her marriage, and push her to the edge of suicide.

One year after Mrs Power, her daughters, and mother were killed, Mrs Lewis and her husband were arrested. They were later released without charge and the mother-of-twins insisted she ''told the truth from day one''.

Mrs Lewis, a former Welsh women's rugby international, sobbed uncontrollably as she told the jury: ''South Wales Police wrongly branded me a murderer of four people I loved. But my only guilt was that I was not there to protect them. I have been as open and honest as I could have possibly been.''

Mrs Lewis was a powerfully-built former policewoman who excelled at sport and regularly worked out at the gym.

The martial arts expert and former British karate champion had met her husband on a police training course. They married in the late 1980s and she moved from her home in Pontypridd to West Crossways, in Pontardawe, in the Swansea Valley, to live and work with her husband.

After leaving the police with a stress-related illness in 1992, Mrs Lewis took up women's rugby again, playing for several local teams and becoming a Wales women's international after only her seventh match.

Women's rugby in the Swansea Valley took place against a vibrant gay and lesbian scene through which Mrs Lewis eventually met Mandy Power, a ''sexual adventurer'' who had been involved with a series of casual and serious lovers.

The divorcee apparently turned her back on heterosexual sex after meeting Mrs Lewis when a lesbian friend called Big Ali invited the former policewoman to a tarot card reading session at Mrs Power's home in Kelvin Road, Clydach, in November 1998.

Within a week they were besotted and began an ''intense'' lesbian affair which was to last until Mrs Power was murdered less than eight months later.

Mrs Power had told a close friend she was like ''a silly little girl in love''. She had married Michael Power, a baker, in the mid 1980s and set up home in the Swansea Valley village of Clydach, where she was born. The couple had two children.

But by April 1998, when Mrs Power moved to the home in Kelvin Road, Clydach, which she was renting at the time of the murders, the marriage was over and she was playing the field.

She met Mrs Lewis after a series of heterosexual affairs. Margaret Jewell, Julie Evans, and Sandra Jones, Mrs Power's three elder sisters, all told the trial she was happy and contented in the days before her death.

However, her eldest sister, Sandra Jones, told the court she believed Mandy's switch to lesbianism was nothing more than ''a cry for attention''. Patrick Harrington QC, prosecuting, said of the couple: ''They became friends, and in a short time they became close friends.

''Whatever the first perception of Alison Lewis, within a very short time, perhaps within a week or so, they were involved in a full-scale lesbian relationship.''

When she learned of her lover's murder in June 1999, Mrs Lewis tried to jump to her death from the bedroom of her home. A day later she was admitted to the Cefn Coed psychiatric unit in Swansea, where she stayed for some time, returning to live with her parents on being discharged.

Mrs Lewis's husband, Stephen, learned simultaneously of the murders, his wife's sexuality, and her secret affair with Mrs Power when police arrived to question her on the day of the killings.

Mrs Lewis and her husband, an acting inspector, were both arrested on suspicion of murder but were later released.

Stephen Lewis told the jury that within one month of discovering what his wife had been doing, he had filed for divorce.

The couple are now divorced, with Mrs Lewis having custody of their twin daughters. She lives close to the home of her parents near Pontypridd.