POTENTIAL police recruits are to sit a racism test in a bid to prevent bigoted officers joining the force.

All Lancashire police hopefuls undergo psychometric tests - a series of questions designed to scientifically test abilities such as intelligence and reasoning.

Now Lancashire Police is taking the unusual step of altering the procedure so that they also check for racist tendencies.

The move follows the outcry which followed a BBC TV documentary The Secret Policeman, which last year highlighted racist behaviour in other forces.

But a psychology expert today said the tests would be unreliable because

people could 'cheat' and offer the answers they thought they were expected to give.

The move is one of 48 objectives set by senior management who reviewed the force's recruitment processes to ensure no racists were slipping through the net.

The BBC documentary showed six police officers filmed at a police training centre used by a number of forces, including Lancashire, making racist remarks. One officer was even caught wearing a Ku Klux Klan-style hood.

Even though none of his officers were involved, Lancashire Chief Constable Paul Stephenson admitted his force may have racist officers and ordered the inquiry into the force's recruitment processes as a precaution.

There are only 93 ethnic minority officers in the county out of the force strength of 3,380.

With a massive recruitment drive currently being carried out to readdress the imbalance, police say it is critical that the force shows racists are not tolerated. A report to the police authority says: "Although none of the officers shown in the programme were Lancashire officers, the programme caused considerable offence to many people we serve in Lancashire and those who work in the constabulary.

"Many officers feel their professionalism and integrity, developed over many years hard work, have been called into question by the mindless racist behaviour of those few officers." But Oxford-based Professor Alick Elithorn, an expert in neuropsychology who has done research in this field, said the tests were unreliable because people could tell what answers they should give.

He added: "It is really difficult to devise tests that intelligent people can't see straight through. A spokesman for the Association of Chief Police Officers said: "The test isn't guidance from us, but I don't know if any other forces are doing that."

Coun Salim Mulla, who is secretary of the Lancashire Council of Mosques, welcomed the tests, but said he felt generally there was not enough dialogue between new police recruits and members of the ethnic minority communities.

The ward councillor for Queen's Park, Blackburn, added: "The tests show the police want to make a difference, but I still think there needs to be a closer link.

"Years ago a sergeant used to ring me up and say he had several new recruits, could he bring them to a mosque to show them around."