NORTH-EAST police chiefs are calling for tougher measures to help root out the region's racist police.

Four forces yesterday urged Centrex, the body responsible for police training, to carry out more stringent attitude tests on recruits.

The move follows the BBC1 TV documentary The Secret Policeman, shown on Wednesday, in which trainee officers were filmed making racist comments while at a police training college.

Five officers serving with forces in Wales and the North-West have since resigned.

The chief constables of Durham, Cleveland, North Yorkshire and Northumbria joined colleagues across the UK to condemn the behaviour.

Superintendent Mick Sedlatschek, of Cleveland Police said: "We do have racist officers and any force that claims otherwise is lying. We go through a very rigorous programme but it is impossible to weed all of them out."

Durham Chief Constable Paul Garvin said: "It is sickening to think of the potential damage caused by the conduct of the officers featured in the documentary.

"Such views and behaviour are totally unacceptable in today's police service."

All recruits to the region's four forces are trained by Centrex at Durham Police headquarters in Aykely Heads. It sends any recruits suspected of racist behaviour back to their force, where they face a disciplinary panel.

Assistant Chief Constable of North Yorkshire Peter Bagshaw said: "We are human, and like all humans we are fallible. But I wish to make clear that as individuals and as an organisation, this force is firmly opposed to racism and racists."

Northumbria Chief Constable, Crispian Strachan, said: "Northumbria Police makes it clear to all staff that racist behaviour in any form, whether inappropriate language, harassment or discrimination, will not be tolerated."

The force has a confidential hotline for officers to report racism and questions all recruits on diversity awareness.

Today, Durham Police will launch a protocol to be followed during the investigation of race hate and religiously aggravated crimes.