The incident once again highlights the reality of 'forced marriages', 'arranged marriages' and 'honour killings' prevalent among sections of the Asian community in Britain, according to an IANS report from London.

The conviction also brings out the cultural divide between parents from the Indian sub-continent and their British-born children.

In this case, the daughter, Manna Begum, 20, had been dating Arash Ghorbani-Zarin, 19, an Iranian-origin student of electronic engineering at Oxford Brookes University, and had become pregnant.

Begum was supposed to marry someone else through an 'arranged marriage' but had continued to date Arash.

This enraged Begum's father, Chomir Ali, 44, who apparently egged on his two sons, Mohammed Mujibar Rahman, 19, and Mamnoor Rahman, 16, to kill Arash.

Arash was found dead in his car in Rosehill, Oxford, with 46 stab wounds in November 2004.

A jury at the Oxford Crown Court took four-and-a-half days to reach a verdict of life imprisonment for Chomir Ali and his two sons.

Justice Gross said the Western-style relationship caused a "battle of wills" in Begum's family, as she refused to conform. The relationship "broke religious and family taboos".

The jury at Oxford crown court was told that Mamnoor's DNA was found on the butterfly knife used to kill him and that bloodstained clothing belonging to the brothers was found in a plastic bag.

Begum and Arash were described by friends as devoted to each other. They wanted to marry and did nothing to hide their affection, often holding hands. This, the jury was told, "brought shame on the family".

Mujibar was said to be furious at his sister's "blatant" defiance and slapped her three times when she refused to end the relationship.

In a police interview, he said: "She acted contrary to religion and tradition by dating Arash. Instead of dating, she should have waited to have an arranged marriage."

Prosecuting lawyer Julian Baughan said: "Their relationship brought shame and dishonour on the family. That drove the accused to murder Arash to vindicate the family's honour."

"It is inconceivable that a murder of this kind would have been organised by his 15- and 18-year-old sons (their ages at the time) on their own. It had all the hallmarks of a family killing with the father egging the boys on."

There were shouts of delight when the verdict was announced on Friday and later the family of Arash issued a statement through police.

They said: "Our son was intelligent and loving and had a wonderful lifetime ahead of him. We miss him every second, every minute and every hour of every day. His death has crushed our family. This verdict gives us back some comfort that justice has been done but it does not bring him back."

Jomsed Ali, 60, a member of Oxford's Bangladeshi community, told the media that the actions of Chomir Ali and his sons had been condemned.

"What he did is very bad, for his family and his community. This is the first time I have ever seen this. I have never known it in Bangladesh either."