EXTREMISTS in the British National Party (BNP) will exploit new open government laws to unmask "moles" who provide crucial intelligence, police chiefs fear.

Senior officers are worried that the far-right party - which is active in Sunderland and elsewhere in the North-East - will use the Freedom of Information Act to carry out "mosaic attacks" on its enemies.

From January 1, individuals and organisations can demand to see information held about them by public bodies, including the police.

The Government insists safeguards are in place to block the release of sensitive information which could pose a security risk.

But the Association of Chief Police Officers (ACPO) fears the BNP will get around this by asking a series of apparently innocuous questions to different forces across England.

When compiled, this data could lead to the "jigsaw" identification of vital informants or the source of criminal complaints, it told MPs.

Deputy Chief Constable Ian Readhead, an ACPO spokesman, said: "What we are particularly concerned about, and we have seen this in New South Wales in Australia, is what are called 'mosaic' attacks.

"What they have experienced there is, for example, a right wing group made 30 separate requests for information on paedophiles.

"Each request in its own right did not reveal that much, but when you put all 30 requests together what it revealed was the source of the intelligence."

ACPO also fears the Act could be used to challenge the recent ruling by police forces that officers should not be members of the BNP.

The party stood a record 57 candidates across the North-East in last June's local council elections, including 25 in Sunderland, one in every ward.