A man found hanged after four years as a suspect in the Jay Abatan death probe had pleaded with his lawyer: "When will this stop?"

Associates of Graham Curtis, who was accused but never convicted of killing Eastbourne father-of-two Mr Abatan in 1999, say the pressure of the investigation contributed to his suspected suicide.

Mr Curtis was arrested and charged with Jay's manslaughter but the case collapsed before reaching court.

Detectives, who were later criticised for a series of failures in the investigation, continued to keep him under surveillance.

Mr Curtis' home in Brighton was raided and "turned upside down" by officers who seized computer equipment and checked his mobile phone calls.

Friends and relatives, some from as far away as Australia, were visited by police who asked about his movements.

Solicitors and a close friend have told us how the continuing inquiry over had "got to him".

Mark Owen, a friend and work partner, said Mr Curtis had suffered inner turmoil.

He said: "Graham had years of it, of police asking questions, and it had an cumulative effect on him."

He said Mr Curtis, 40, had described Jay's death, which started with a row over a taxi outside the Ocean Rooms nightclub in Morley Street, Brighton, as a tragedy.

Mr Curtis had said a punch was swung in his direction and a punch was delivered in response.

Jay, 42, went down and hit his head on the ground. He fell into a coma and later died from head injuries.

Manslaughter charges against Mr Curtis and a second man failed due to lack of evidence and both were later acquitted of affray. But police interest in both men has continued.

When he recently split from his girlfriend his depression deepened.

Mr Curtis was found dead at his home in Port Hall Road, Brighton, on Saturday last week.

Police said there were no suspicious circumstances.

Peter Bottomley, the West Worthing MP who took up the case on behalf of the Abatan family, said he took no pleasure in Mr Curtis' death but wished he had "told the truth".

He said: "From the moment of their first arrest Graham Curtis and his associates refused to give information which could have led to a prosecution for manslaughter or murder."

Michael Abatan expressed sympathy to Mr Curtis' family but said: "Curtis had a choice to come forward and speak to the police. My brother had no choice that night."

He said the death was a setback for the ongoing Justice for Jay campaign but it would continue.

He said: "If people think Curtis was keeping quiet and protecting the guilty person then now is the time to speak."

Assistant Chief Constable Nigel Yeo, heading Operation Hurling, declined to comment on whether Mr Curtis had been harassed by his officers.

No date for the inquest has been set.