Mark Baigent (27) is alleged to have told Mandy Arzomanides on a holiday to Greece that he, along with his brother James (30) and friend Jeff Woods (36), had killed Andrew Scanlan (35).

On Thursday, Mrs Arzomanides, talking from behind a screen, told jurors at Cambridge Crown Court that she had written everything that he had told her in a special diary when she got back to England.

She said Mark Baigent, of Medworth, Orton Goldhay, Peterborough, had first told her they had killed his hated sibling the day before they left for Greece on November 22, 2006.

She said: “It was something like ‘we’ve got Andrew, we killed him’. He said it in an excited way.”

Mrs Arzomanides said she did not believe him, but began to become concerned as he went into more details of the killing during the trip.

And she said her fears were confirmed when a detective rang her mobile phone when they were driving back to England to ask if she was with Mark Baigent.

It is alleged that the Baigent brothers blamed Mr Scanlan for the death of their mother, Linda, in October 2006.

The prosecution say they tricked him into leaving his home in Dickens Street, Eastfield, Peterborough, on November 17, and drove him down to Aldershot where they, along with Woods, killed him.

Mrs Arzomanides said Mark Baigent began filling her in on the grisly details outside a café owned by her former husband’s family in northern Greece.

Reading from her diary, she said she was told the trio had driven the father-of-three to a remote spot but had “bottled” the attack.

She said Mark Baigent told her he had comforted Mr Scanlan who was becoming “nervous and suspicious”.

“I told him not to worry, that James’ mate only wanted to talk to him. I was there to keep him safe. I assured him nothing would happen to him.

“James had beaten him with a baseball bat. He was saying ‘please, please, think about my little girls’, he kept begging and begging. Kept beating him with the bat but he wouldn’t die. I thought ‘come on’, that’s when I broke his neck.

“He said that Linda had always said, if anyone would ever kill Andrew, it would be James, but I did it.

“We put him in a shallow grave then covered him up.”

Mark Baigent, James Baigent, of Sandhurst, Surrey, and Woods, of Bracknell, Berkshire, all deny murder.

Charlotte Baigent (28), of Sandhurst, Surrey, denies three counts of assisting and offender and perverting the course of justice.

The trial continues.