It was alleged that Mark (27)and James Baigent (30), along with close friend Jeff Woods (36), thought they could get away with strangling and stabbing Andrew Scanlan (35) and then chopping up his body – by using forensic methods they had seen on the American television series CSI: Crime Scene Investigation.

Cambridge Crown Court was told that the three men tricked Mr Scanlan into taking a trip to Surrey on the pretext of sorting out their mother's will – but their plan was to kill the father of three in cold blood and bury his mutilated body in dense woodland.

Mr Scanlan, of Dickens Street, Eastfield, Peterborough was allegedly a "dead man walking" because his half brothers blamed him for the death of their mother Linda (55) on October 18, 2006.

Prosecutor Timothy Spencer QC said the Baigent brothers felt she had been "burdened" with looking after Mr Scanlan's three children because of his poor parenting skills.

Mr Scanlan had also given police a statement which helped convict Mark Baigent of an attempted armed robbery in 1998 for which he was locked up for four-and-a-half years.

Mr Spencer said: "There was, to say the least, a great deal of tension and strain between Andrew Scanlan and the brothers, which must have become simple hatred.

"We suggest the only thing which prevented the hatred for Andrew Scanlan being turned into action was the fact that Linda Baigent was alive and it would be known by these two that their mother would not approve of any harm coming the way of Andrew Scanlan at their hands.

"But once she died, that protection for Andrew Scanlan disappeared and from the day she died Andrew Scanlan was, as Americans say, a dead man walking."

Mr Spencer also said that a close friend of James Baigent had described a conversation the pair had about two weeks before Mrs Baigent died.

He said: "He remembers James Baigent saying to him 'once mum dies he's not family any more – the rules change'.".

After their mother's death, Mark Baigent went to Mr Scanlan's home and warned him to stay away from the funeral in Spalding, where she had been living.

A few weeks later, the plan to kill Mr Scanlan was rolled into action.

Phone records were shown to jurors showing James Baigent travelled to Peterborough from his home in Sandhurst, Surrey, on November 17, 2006.

It is alleged that he took his two young daughters with him as a "cover" for the trip. He is then said to have picked up his brother Mark from Medworth, Orton Goldhay, before going to Andrew's home.

The victim's girlfriend, Louise Burke, told police that the pair had told Andrew he needed to go down to Dorset with them to sort out their mother's will.

However, Mr Spencer said that was merely a "ruse" to get him down to Surrey. On the way down, text messages were sent between James and his wife Charlotte (28).

Special Report: Andrew Scanlan murder trial