The parents of a young man who died after excessive force and restraint was used at a psychiatric hospital have called for the police to be held accountable.

Olaseni Lewis was 23 when he died after being restrained by up to 11 police officers at Bethlem Royal Hospital in Monks Orchard Road on August 31, 2010.

After an inquest lasting 10 weeks at Croydon Coroner's Court, a jury found that police and hospital failings, including use of “unnecessary and unreasonable” excessive force, contributed to Olaseni’s death.

Conrad Lewis, Olaseni’s father, said: “The police can’t go on doing this. We want to see some changes in the system, and the mental system and the police and the way they are trained.

“When you go to the police or hospital for help you don’t expect them to end up dead.

“Let his memory mean something by changing the system. We want accountability and it has to happen now.”

His family have called for the Crown Prosecution Service to look into bringing criminal charges against the officers involved.

His mother Ajibola Lewis said: “It [the inquest conclusion] is bittersweet because we have lost our son and we are never going to get him back and we have heard how he died, so that is good to hear, but it is all very bittersweet and it is now time to get some accountability from the police.

“We want some accountability of the police, we would like the CPS to look into it.

“We just don’t want it to happen to another family, it has traumatised our family, we have had to fight all the way to get to the inquest and they [the police] have obstructed us.

“At least the jury came to a very damning verdict but it is all bittersweet.”

The Lewis family who live in South Norwood fought for seven years to get an inquest for the IT analyst who had a ‘heart of gold’.

Mrs Lewis continued: “He was a gentle soul, he hated injustice and bullies. He was very qualified, nobody had to tell him that he had to study. He was lovely, fun-loving and had lots of friends. He had a heart of gold.”

In a statement posted on the Justice for Seni campaign website the family wrote: “When Seni became ill, we turned to the state in our desperation, we took him to hospital which we thought was the best place for him.

“We shall always bear the cross of knowing that, instead of the help and care he needed, Seni met with his death.

“Now, after almost seven years of struggle to get here, the last three months have allowed us to hear for ourselves about what happened to Seni.

“We have heard about the failures at multiple levels amongst the management and staff at Bethlem Royal Hospital, instead of looking after him, they called the police to deal with him.

“And we have heard about the brute force with which the police held Seni in a prolonged restraint, a restraint that was maintained until Seni was dead for all intents and purposes.

“In light of the evidence we have heard, we consider that the prolonged restraint that resulted in Seni’s death was not and cannot be justified, and we now look to the Crown Prosecution Service to reconsider the case, so that the officers involved in the restraint may be brought to answer for their actions before a criminal court.

“This is necessary, not just in the interests of justice for Seni, but also in the public interest, so that the police are seen to be accountable to the rule of law.”