In an unprecedented move, Paul Whitehouse, Chief Constable of Sussex, and three of his most senior colleagues, are to be interviewed by officers from another force.
The inquiry follows the death of James Ashley, 39, who was shot in the chest by a police officer during an early-morning raid last January at his flat in Hastings, East Sussex. He was naked and had been in bed with a girlfriend when the shooting took place.
The morning after the shooting, which happened at about 4am, Mr Whitehouse backed the operation and said that the officers had been investigating drugs-trafficking and the attempted murder of a man stabbed outside a pub in Hastings. He said that the man they were after was considered "armed and dangerous".
In an extremely unusual move the Police Complaints Authority later issued a statement saying that Mr Ashley, far from being a murder suspect, had pulled the assailant off the victim and prevented a murder.
The solicitor for the family of Mr Ashley complained that the dead man's reputation had been "blackened" by Sussex police.
No gun was found in Mr Ashley's room and just a tiny amount of cannabis was discovered.
Mr Ashley was jailed for two years for manslaughter in 1992. He has no convictions for drugs dealing.
Caroline Courtland-Smith, the 19-year-old art student who was in the bedroom at the time of the shooting, has since suffered a breakdown and has left college. She is to sue Sussex police for damages
Claims for damages are also expected to be made on behalf of Mr Ashley's 14-year-old son, James, who lives in Liverpool.
Sir John Hoddinott, Chief Constable of Hampshire, is leading an inquiry into the "conduct of chief officers in the aftermath of the shooting of James Ashley".
As well as Mr Whitehouse, his Deputy Chief Constable Mark Jordan, and Assistant Chief Constables Nigel Yeo and Maria Wallis are to be questioned.
Sir John's final report, expected to be completed in a few months, will be sent to the Crown Prosecution Service (CPS), which will consider whether charges should be brought. Any disciplinary action will be considered later.
Five officers who were involved in the raid have been suspended and were accused at the opening of Mr Ashley's inquest of "misrepresenting" intelligence leading to the operation.
A separate inquiry by Kent police into the officers' actions is nearing completion and will be sent to the CPS for a decision on whether criminal charges should be brought.
This is believed to be the first time the four most senior officers of a force have been the subject of an investigation.Reuse content