A LOVE-CHEAT policeman told yesterday how he suffocated his common-law wife just three days before they were due to marry. Chong Yan-yuk, 30, killed Maggie Leung Mei-kee, 25, after telling her to call off the registration ceremony, the High Court heard. The policeman denies murder, but admits manslaughter. He claims he suffocated Leung by accident when she attacked him after finding out about his affair. Chong told the jury how his relationship with Ms Leung had become increasingly turbulent after they started living together in 1990. He said she was temperamental, criticised him and refused to sleep with him because he snored. But he agreed to hold a wedding banquet in November 1992 because he wanted to save the relationship even though he was also seeing a 19-year-old student nurse by that time. Chong said he finally decided to confess to the affair with Siu Wing-yan on June 19 last year - just days before Ms Leung had arranged to register their marriage. He said: ''I woke Maggie up. I said I have put up with your behaviour for a long time. We are going to separate. It's impossible for us to stay together. There is a third person.'' He said Ms Leung became angry, hit him and threatened he would die if he left her. Chong added: ''I felt very agitated and felt I was unable to control myself.'' He said he had pinned her down on the floor after she started throwing objects at him in her parents' flat. ''After a while, when I became a bit calmer, I discovered Maggie was motionless. I noticed her fingers were a purple colour. ''I was very frightened. I knew that I had taken a person's life and I knew I would have to be sent to prison.'' The trial before Mr Justice Saied continues today.