Six members of a Metropolitan police crime squad under investigation in a major anti-corruption inquiry are to keep their jobs after being found guilty at a secret disciplinary hearing of smashing up a suspect's car with a baseball bat and a pickaxe handle.

The six, a detective sergeant and five police constables, are the first in a string of officers to face disciplinary hearings following a 16-month anti-corruption inquiry into 15 members of the Enfield crime squad in north London.

The investigation, which began in May 2008, involved 43 separate inquiries into allegations made by a whistleblower that detectives had assaulted and abused suspects, used excessive force to stop a stolen car, and taken property for their own use in the police station, including cars such as a Mercedes, flat screen televisions and other electrical goods. The inquiries were supervised by the Independent Police Complaints Commission.

Three superintendents, who were borough commanders of the area during the period the squad was active, were interviewed as witnesses and legal sources said the managers had been "generally aware" of what was going on. But none have been reprimanded and all three have since been promoted to chief officer rank.

It can be revealed that after a seven-day Metropolitan police misconduct hearing, held behind closed doors, the first disciplinary hearing in the case has found the six officers guilty of discreditable conduct for using excessive force to stop a stolen car. But the panel, made up of senior officers and a lay member from the Metropolitan Police Authority ruled that all six could remain on the force, the Met said on Wednesday.

One officer has had his rank reduced from detective sergeant to detective constable, the five others have been formally reprimanded after the allegations of discreditable conduct were found proven, Scotland Yard said.

Video footage of the six launching an attack on a stolen car driven by Jonathan Billinghurst was uncovered during the anti-corruption inquiry when, after 10 months of surveillance, including bugging the unit, officers from the Met's directorate of professional standards executed search warrants at Edmonton police station.

Within the crime squad they found the footage, which had been filmed as part of police procedure during some arrests. But the contents of the footage are a long way from police procedure.

The six officers, including one female officer, are seen driving an unmarked car and are seen in a traffic jam on Meridian Way, in Edmonton. One of the officers shouts, "attack, attack", before all six leap out of the car, carrying a baseball bat and a pick axes handle, and proceed to smash the passenger side window, the windscreen and the passenger door of the Mini being driven by Billinghurst.

The sound of Tracey Chapman's track Fast Car can be heard as the officers arrest the suspect. They denied doctoring the video to add the music afterwards.

At least one of the officers is seen wearing an anorak with the words "Crime Squad" written in white across the back in a homemade copy of the jackets worn in some American police dramas.

Billinghurst was being targeted, the detectives claimed, because they had intelligence that he had a history of carrying weapons, had made death threats to the police and had threatened to shoot an officer. Billinghurst's brother had been killed two years before on Meridian Way in a head-on collision and the officers claimed that their intelligence showed he held a grudge against the police because a police car was involved in the crash.

Anti-corruption officers found nothing to support any of the so called intelligence which the six officers claimed to have gathered.

The inquiry, which centred on "disproportionate, unnecessary and inappropriate" action by the crime squad, gathered significant evidence which it passed to the Crown Prosecution Service. But last year the CPS said it would not be bringing charges against any of the officers involved. The misconduct hearing found the detective sergeant had "failed to property supervise five officers by allowing them to use baseball bats and a pick axe handle" to carry out the stop and detain the driver.

The five officers were found to have used "more force than was reasonable or necessary".