No action on Enfield Police 'waterboarding' allegation
Three Enfield police officers accused of "waterboarding" a suspect will face no further action after the main witness refused to give evidence.
The Independent Police Complaints Commission (IPCC) began investigating several corruption allegations after the incident in 2008.
A suspected drug dealer allegedly had his head held down a toilet at a property in Brantwood Road, Tottenham.
But the misconduct action has now been halted by the IPCC.
Criminal charges were dropped in 2010 due to a lack of evidence.
Prosecutors and the IPCC have both launched inquiries into claims of corruption by members of the Enfield crime squad.
Police have also faced claims that they assaulted suspects and took their property, including a Mercedes car, for their own use.
The misconduct hearing had focused only on the lavatory incident, which the suspected drug dealer described as a waterboarding.
Police had been accused of flushing the toilet once his head was inside the bowl.
IPCC commissioner Mike Franklin said: "This particular investigation was solely looking at the incident in Brantwood Road and not other incidents involving Enfield crime squad.
"The IPCC was in the process of consulting those involved in the search with a view to holding a misconduct hearing for the three officers in public.
"Powers provide for the IPCC to direct a force to hold a misconduct hearing in public if it is in the public interest to do so because of the gravity of the case."
He continued: "Regrettably, in this particular case, the main witness has declined to provide their evidence to a hearing.
"It is therefore unfortunate that the Metropolitan Police Service will now not be able to hold misconduct proceedings as previously planned."
Waterboarding was used on prisoners by the US Bush administration as an "enhanced interrogation technique", although many regard it as torture.
It involves a prisoner being hung upside down with water poured into his nose and mouth to simulate drowning.