A man who took part in a chilling knifepoint robbery has been jailed for almost four years.

Kai Griffiths faced a long prison sentence for the robbery on Brighton beach in which the vulnerable victim's throat was cut with a knife.

But a judge ruled yesterday it would be inhumane to send him to prison for longer.

Judge David Rennie said he had cut the sentence due to Griffiths' psychiatric problems.

Griffiths, 26, was convicted of robbing Stephen Harris after a trial at Lewes Crown Court.

He was due to be sentenced on January 16 but smuggled a razor blade into court cells.

It was found just before he went into the dock, where he intended to kill himself by slashing his throat.

Griffiths, of North Road, Portslade, handed a letter in the cells to his barrister Philip Wakeham to pass to Judge Rennie.

The blade was discovered after Mr Wakeham read the letter in which Griffiths made clear what he intended to do.

Mr Wakeham said yesterday that Griffiths had been bullied in prison as a result of rumours spread by Jamie Pearce.

Pearce, 25, of Brunswick Terrace, Hove, was cleared of taking part in the robbery in July 2004, but is awaiting sentence on other charges.

Mr Wakeham said because of the bullying, Griffiths was in the segregation wing at Lewes prison for sex offenders.

He added: "Mr Griffiths was abused when he was a child and as result he has found it much more difficult to cope.

"If that segregation continues in a lengthy sentence, it is likely to have a much greater impact on him than any other prisoner."

Judge Rennie jailed Griffiths for a total of three years and 11 months for the robbery and for escaping from Ford open prison for driving while disqualified.

He said: "I agree you will find your time in prison particularly difficult. For that reason ... I think it would be inhumane for me not to reflect that by some reduction in the sentence."