HAYLEY MURDER TRIAL: A Portuguese factory worker who slit the throat of his pregnant girlfriend told a jury that he suspected she was cheating on him.

Hugo Quintas, 25, said he thought Hayley Richards was sleeping with one of her colleagues after hearing a man's voice in the background when he phoned her. He also doubted the baby was his after the waitress told him she was pregnant last May, Bristol Crown Court heard.

The 23-year-old was found dead at her flat in Trowbridge, Wiltshire, on June 11. Her throat had been cut from ear-to-ear by Quintas, who fled the country a day after the killing.

He has pleaded not guilty to murdering his girlfriend, but has admitted her manslaughter on the grounds of provocation.

Giving evidence for the first time during the trial, Quintas told the court that he had met Hayley in September 2004 in a pub in Trowbridge and slept with her on that night.

Speaking quietly thorough an interpreter, he said he realised two days after they had sex that he had caught two sexually transmitted diseases from her. He said he immediately began to doubt whether they had a ''respectful relationship'' after he tested positive for gonorrhoea and chlamydia.

Quintas, who arrived in England in June 2003 to work at a food factory in Trowbridge, said he had discussed having a baby with Miss Richards shortly before they went on holiday to Portugal and Spain in March 2005.

He said she had been pregnant before during a previous relationship and had suffered a miscarriage. Quintas told the jury that it was not long after the holiday, that he started to suspect she was having an affair with a chef, he knew as Rich, at the restaurant where she worked.

He said he had phoned her and heard a man's voice in the background and challenged her about it when he returned home from work. Asked if he suspected something was going on, he said: "Well, I did suspect a little but I had no proof."

Quintas' friend, Portuguese dairy worker Joaquim Sergio Da Cuhna, 30, also appeared in the same court accused of perverting the course of justice. He denies washing Quintas's clothes, buying flight tickets and helping him travel to Bristol International airport after the alleged attack.