Four police officers have been suspended ahead of a BBC programme which alleges racism at a training centre.
The programme alleges one officer wore a Ku Klux Klan mask
Greater Manchester Police (GMP) said it suspended three officers after senior officers viewed footage from The Secret Policeman programme.
North Wales Police has also suspended one officer as a result of the footage.
GMP said the officers would be suspended pending an internal investigation and added they would take further action against any other officers shown making racist comments.
It follows the arrest of 28-year-old BBC reporter Mark Daly who was caught working undercover as a probationary constable in the force's Stockport division.
The programme alleges an officer dressed in a Ku Klux Klan mask at the police training centre in Warrington while Mr Daly claims to have recorded racist comments made by some officers.
GMP said it had obtained footage of the programme, which is due to be shown on Tuesday, from a source outside of the BBC.
Deputy Chief Constable Alan Green said: "We are disappointed that, despite repeated requests, we have not yet received a copy of the programme from the BBC to enable us to take immediate action.
"However, in the light of the information we have received from elsewhere, we have no hesitation in suspending these officers pending a thorough investigation.
"We have always made it clear that any racist behaviour in whatever form will not be tolerated within Greater Manchester Police.
'No place for racists'
"We will be unrelenting in our actions against racism both inside and outside the Greater Manchester Police service."
North Wales Police Deputy Chief Constable Clive Wolfendale said: "If the BBC has evidence of racist behaviour by a North Wales officer, we would want to act on that immediately.
"There is no place for racists here. Even though we have still not seen the programme or had any evidence from the BBC, our internal information is such that we have suspended the officer until the facts and identity are clear".
The investigation will be supervised by the Police Complaints Authority.
Mr Daly spent five-and-a-half months with GMP and is suspected of obtaining a pecuniary advantage by deception and damaging police property.
He is due to answer bail in November.
The BBC has said any pay Mr Daly received has been kept in a separate bank account and was to be returned to the force at the end of the investigation.
It has also offered to pay for damage caused to Mr Daly's bullet-proof vest, which was altered to hold a pinhole camera and battery pack.
The Home Office also criticised the BBC for not releasing footage of the programme and said the decision to suspend the officers came after Home Secretary David Blunkett called on both forces
to take "decisive action".
A Home Office spokeswoman said: "The Home Secretary... is grateful that as of this afternoon, the officers alleged to have been involved have been suspended."
She added: "We have always said that all allegations of racism are taken extremely seriously and that immediate action would taken to root out racism in the service.
"We will continue to work closely with police forces and with the CRE
(Commission for Racial Equality) to help expose and tackle any racism which remains in the service."