Five police officers and a solicitor could face criminal charges over the death of a man restrained and forced to the ground during a routine stop-and-search operation six years ago.

The officers face possible charges of manslaughter and perverting the course of action after it emerged that they had changed their initial accounts of how Habib Ullah, 39, died at a car park in High Wycombe in July 2008.

Mr Ullah, who was with a group of men in a car, went limp after he was forced to the ground and restrained by officers who thought that he had drugs in his mouth. He died later in hospital.

Download the new Independent Premium app Sharing the full story, not just the headlines

The Independent Police Complaints Commission (IPCC) confirmed yesterday that it had passed a file to prosecutors. The watchdog had carried out an earlier investigation but found in 2009 there was no case to answer against the officers from Thames Valley police, who remain on duty. They were not questioned during that inquiry.

An inquest heard the following year that police removed potentially vital information about the death from their initial accounts of the death on the advice of their solicitor. The inquest was abandoned and the IPCC launched a second inquiry.

The IPCC said that it had investigated the discrepancies between officers’ statements and their accounts at inquest. The inquiry also investigated the level of force used against Mr Ullah after key details about his behaviour during the stop were taken out of the statements.

The family of Mr Ullah, of Slough, Berks, wrote to the IPCC last month to express their frustration at the time the inquiry was taken.

“We have been waiting very patiently and really need an end to all this investigation. It’s been five and a half years and we want closure on Habib's case this year,” the family said.

“As the children are getting older they deserve justice for their father and we need answers. We have lost a valuable and loved member of the family and we will not stop fighting until this has been done.”

It is believed that the Crown Prosecution Service is likely to consider charges including gross negligence manslaughter for the officers. The officers and the solicitor could also potentially face charges of perverting the course of justice.

The watchdog’s deputy chairwoman Rachel Cerfontyne said: “I am very sorry for the prolonged distress this has caused, but it has been essential to ensure that our investigation was robust and thorough.”

Thames Valley police declined to comment on the inquiry but said it had worked closely with the IPCC.

The solicitor, who has not been named, has been reported to the solicitors’ regulator for possible misconduct charges.

The case has echoes of the inquiry into Sean Rigg who died in police custody in 2008 but the IPCC initially ruled out disciplinary action for police officers.

An inquest subsequently found that officers used unsuitable force and an independent review criticised the IPCC’s initial inquiry. The IPCC reopened its investigation into Mr Rigg’s death in December.