THE police whistle-blower who claims Cleveland's chief constable is implicated in a "dirty tricks" campaign against suspended detective Ray Mallon is a woman with 13 years service in the force, it was revealed yesterday.

The force's head of media affairs, Joanne Malone, 37, has used the Public Interest Disclosure Act to lodge a complaint against Chief Constable Barry Shaw and two other members of staff.

She claims Mr Shaw authorised the leak to a national newspaper in June of a confidential report critical of Detective Superintendent Mallon's style of zero tolerance policing.

On Friday, her complaint triggered an investigation into Mr Shaw's conduct by the Chief Constable of South Yorkshire, Michael Hedges, appointed by Cleveland Police Authority. The inquiry will be overseen by the Police Complaints Authority.

It is believed other members of Cleveland Police staff are also to be investigated.

The latest probe follows the lengthy suspension of Mr Mallon and seven other detectives from Middlesbrough while they are investigated as part of the £5m Operation Lancet inquiry.

Mr Mallon has been cleared of any criminal wrong-doing, but remains suspended as an internal inquiry continues. One of the allegations is that Mr Mallon passed confidential information to the press.

The appearance of the Treasury Counsel report about Mr Mallon in the Daily Express came on the day he held a press conference after he was cleared of any criminal behaviour. Mr Mallon's supporters claimed at the time that the report was leaked to discredit him.

In contrast to Mr Mallon, Mr Shaw has not been suspended from duty by Cleveland Police Authority.

Mrs Malone, of Hutton Rudby, North Yorkshire, declined to comment