Pc Pulling was shown wearing a Ku Klux Klan mask in the programme
Five police officers have resigned and three have been suspended, after an undercover BBC documentary revealed racism among police recruits.
The first to resign was Pc Robert Pulling of North Wales Police, who was shown dressed in an improvised Ku Klux Klan hood and making a string of racist comments.
He was followed later on Wednesday by three unnamed officers from Greater Manchester Police, and Pc Steve Salkeld from the Cheshire force.
A further North Wales officer and two more from the Manchester force were also suspended after being shown making racist comments.
All three forces involved strongly condemned the behaviour shown on the film The Secret Policeman, broadcast on Tuesday, and promised to do more to banish racism.
Home Secretary David Blunkett said the racism was "horrendous" and urged better training for recruits.
WATCH THE PROGRAMME
Click below to watch extracts from the programme. Some extracts contain strong language
In the documentary, undercover reporter Mark Daly filmed Pc Pulling admitting being racist, voting for the British National Party and saying Hitler had the "right ideas".
North Wales Deputy Chief Constable Clive Wolfendale said the programme had made him feel "physically sick".
"Pulling has shamed his colleagues, his uniform and his service. He is a disgrace," he said.
He said Mr Pulling had already been suspended because of concerns about his attitude, and had never undertaken unsupervised operational duties.
Deputy Chief Constable Alan Green of Greater Manchester Police said he had been "shocked, ashamed and very saddened" by what he had seen, and promised a full investigation.
He said while the majority of his officers were hardworking and not prejudiced, "we need to do more" against racist officers.
He added: "We will use any tactics we possibly can, to root them out.
"This is a big wake-up call for us and I know [Chief Constable] Michael Todd is determined we will leave no stone unturned in rooting out these people."
This is a big wake-up call for us
Deputy Chief Constable Alan Green, Greater Manchester Police
Cheshire Assistant Chief Constable David Griffin said racist conduct, whether inside or outside the police service, was "abhorrent".
He said: "There is great disappointment and anger at all levels within the police service that a small group of officers, including one from Cheshire, have let us all down."
'Horrendous'
Home Secretary David Blunkett had previously criticised the BBC for its methods of reporting, questioning whether its intent was "to create, not report" the story.
But on Wednesday he said: "The issue now is not how this was done [undercover] but what we can do... to ensure police services across the country root out racism."
RECRUITS IMPLICATED IN BBC DOCUMENTARY
Pc Steve Salkeld (Cheshire)
Pc Andy Hall (GMP)
Pc Adrian Harrison (GMP)
Pc Carl Jones (GMP)
Pc Tony Lewin (GMP)
Pc Andy Turley (GMP)
Pc Keith Cheshire (N Wales)
Pc Robert Pulling (N Wales)
Mr Blunkett said a new training scheme on diversity should be adopted across the country to root out racists.
The Police Superintendents' Association of England and Wales called upon chief constables across the country to uncover any serving racist officers and dismiss them.
President elect of the association, Rick Naylor, said: "We will not tolerate racism in any shape or form. We find it abhorrent and there is no place for it in a modern police service."
His comments were echoed by Sir John Stevens, commissioner of the Metropolitan Police and the UK's top police officer.
"I have been a policeman for 41 years at the sharp end and I was absolutely astonished at that behaviour," he said.
"I have never heard that type of conduct or behaviour and that type of racism - if I had, I would have arrested them for it."
I have been a policeman for 41 years at the sharp end and I was absolutely astonished at that behaviour
Sir John Stevens, commissioner of the Metropolitan Police
Sir John also revealed that the Met intends to plant informers in its own training classrooms to root out racist recruits.
Their identities will remain secret for the rest of their careers and they will act as intelligence gatherers.
Mr Daly, 28, joined Greater Manchester Police as a trainee officer and secretly filmed recruits at Bruche National Training Centre in Warrington, Cheshire.
Mr Wolfendale added that the North Wales force would be writing to the family of murdered black teenager Stephen Lawrence to apologise for "obscene" comments Mr Pulling had made.
However, he also criticised the BBC for not telling the force what it had uncovered before the programme was broadcast
The Secret Policeman 
This is a big wake-up call for us 
