A man accused of murdering his parents in a fit of rage tried to paint himself as a master criminal in a series of bizarre letters written in his prison cell, the Old Bailey heard today.

The jury heard Daniel Dighton attempted to buy psychiatric case notes from a fellow prisoner for £10,000, and scribbled love letters to his second cousin telling her they would have “everything they had wanted” when he came out.

Mr Dighton stabbed his mother Elizabeth, 60, more than 20 times at the home they shared in Campden Road, South Croydon before turning on and killing his 61-year-old father Barry.

Joel Bennathan, defending, said the letters were complete nonsense and another example of Mr Dighton being a compulsive liar.

He said: “Danny Dighton is a slightly slow man who makes up stuff even when he is in familiar, non-threatening places like The Folly pub.

“Then he's in a prison. No longer a familiar and non-threatening place of course, it's a new and potentially terrifying place.

“The obvious thing for him to do is what he does in the pub: to make up stuff that will make him feel safe.

“He can either paint himself as an oddball or a master criminal.”

The court heard the defendant's second cousin, Cassie Dighton, had visited him in Highdown prison out of pity, and because she thought it was what the parents he murdered would have wanted.

One letter read: “Dear beloved Cassie.

“I'm fine, I hope you are well.

“I remember the good times we had together, especially in Thailand.

“I hope we will go back again and find our dreams.”

Mr Bennathan said psychiatric evidence showed Mr Dighton had killed his parents while suffering from an acute stress reaction.

The court heard this was caused when Mrs Dighton called her son a ****ing idiot and threw a book at him during a row over packing for a holiday.

Mr Dighton denies murder, claiming manslaughter on the grounds of diminshed responsibility.

The trial continues.