Mark Doyle left Ireland after being warned he would be killed if he gave evidence in the trial of Karl Breen, 27, who was convicted yesterday of the manslaughter of Martin McLaughlin at Jury's Inn, Croke Park on 1 January 2006.

Breen admitted stabbing the 21-year-old three times but denied murder. He was found guilty of manslaughter and will be back in court on Wednesday to receive a date for the McLaughlin family's victim impact statement.

The victim's father, Martin senior, said after yesterday's verdict: "Martin was a quiet fellow who had just turned 21.

We're not coping very well at the minute; we're doing the best we can." He added that the family would have to accept the court's decision. "That's the law and that's what has to be done."

As one of the state's key witnesses, Mark Doyle endured 18 months of threats and intimidation aimed at preventing him from testifying. His home in Clondalkin, Dublin, was shot at twice and he was warned he would be murdered if he gave evidence in court. There is no suggestion that Breen was involved in any incident.

The last shooting incident happened just two days before the case began and Doyle received regular phone calls and text messages from unknown people warning him to leave the country. Graffiti appeared on walls in Clondalkin mentioning Doyle. The innocent Doyle was in fear of his life and has now left the country; he is thought to be in Spain.

Doyle and Karl Breen were friends and Breen sent Doyle a text message while Martin McLaughlin was in hospital fighting for his life. Breen labelled McLaughlin's girlfriend Elaine Fagan a "rat" and blamed her for starting the fight.

The court heard that a large amount of alcohol had been consumed on the night of the killing. Breen and McLaughlin were captured on a CCTV camera hugging shortly before the fatal fight broke out.

The written statement given by Doyle to gardai was read into evidence during the case.

He described receiving phone calls from Breen but said: "I told him to f*** off, I didn't want to talk to him".

Gardai investigated several incidents of witness intimidation in the McLaughlin murder case and several witnesses' cars were burnt out in the weeks before the trial got under way at the Central Criminal Court.

Gardai took the intimidation so seriously that armed officers regularly patrolled outside the homes of some of those who were due to give evidence.

It took the jury five-and-ahalf hours to reach their verdict, having stayed overnight in a hotel on Friday, and they returned to Judge Kevin O'Higgins several times with questions about the case . . .

including a request to review the footage of Breen and McLaughlin hugging just minutes before the stabbing.

When the verdict was announced, Breen's girlfriend, who is pregnant, clasped her hands to her face. Breen looked at the jury and nodded slowly several times. No-one from Breen's family attended the trial and they were not present for the judgement.

Karl Breen has 92 previous convictions for minor offences such as public order offences and road traffic incidents, and is well-known to gardai across west Dublin.

He was once described by a judge as "brutal, mean and nasty" after he was convicted of being one of the key organisers in a dog-fighting ring. He was arrested after gardai raided a barn at Robertstown, Co Kildare, in October 2003. Gardai found two pitbull terriers that were badly injured and emaciated. Eleven people who attended the fight were arrested. A special ring had been built and carpets put down to give the animals a better grip while fighting.

A judge told Breen that his presence at the dog fight "was not an act of innocence but by arrangement. It was not a minor offence in my view. It is a mean and nasty offence where innocent animals are used for a purpose never designed for them".

The jury in the case found him guilty of two acts of animal cruelty and he was given a nine-month prison sentence, which was suspended on condition that he pay 5,000 to the ISPCA.