A man has been found dead in his cell just days after he was jailed for manslaughter.

Gareth Russell, 25, was found hanging by his cellmate just after midnight today.

Staff at Lewes prison desperately tried to revive Russell and called an ambulance at 12.07am.

He was taken to the Royal Sussex County Hospital, Brighton, but doctors were unable to save him. He was declared dead just after 1am.

Russell, an alcoholic, had been living rough in the Brighton area for some time.

He was found guilty of the manslaughter of Terry Hannaby, 34, on Thursday after a seven week trial at Hove Crown Court.

A judge said he had stood "shoulder to shoulder" with Anthony Griffiths, 33, and Andrew Stanley, 40, during the attack in Bartholomew Square, Brighton.

Mr Hannaby's body was found under a blood-soaked duvet by security staff as they let early morning cleaners into Brighton Town Hall.

He had been kicked and stamped to death during the brutal attack on September 4.

Stanley and Griffiths, also street drinkers of no fixed abode, were found guilty of murder after the jury spent three days considering its verdicts.

They were jailed for life and will have to serve a minimum of 12 years before they are considered for release on licence.

Russell was found guilty of manslaughter and was sentenced to six years for his part in the attack.

The court heard he had suffered brain damage from trauma and alcohol abuse which could have affected his control over his actions.

An investigation into his death in custody has been launched by the Home Office.

A spokeswoman said: "Gareth Russell was found hanging in his cell at 12.05am.

"Staff immediately attempted resuscitation, paramedics attended and he was taken to hospital.

"Unfortunately, he failed to recover and was pronounced dead at 1.10am.

"Any death in custody is a tragedy and our sympathies are with the family of Mr Russell at this time.

"As with all deaths in custody the Prisons and Probation Ombudsman will conduct an investigation."

Russell was the third Sussex prisoner to die in custody this month.

Dafydd Field, 52, who was charged with the murder of his six-year-old son Jethro, was found electrocuted in his cell at Lewes on April 10.

Emma Kelly, 31, from Heathfield, was found hanging in her cell at Send prison in Surrey on April 18.

She was eight months into a nine year sentence for supplying cocaine and heroin to her son from the age of nine.