SCOTLAND’S top police officer is facing a fourth misconduct investigation.

The Police Investigations & Review Commissioner (Pirc) said it had been asked to assess a new allegation levelled against Chief Constable Phil Gormley.

The Pirc is already investigating three allegations of bullying and misconduct against Mr Gormley, who has been on special leave since September.

He has strongly denied misconduct, calling complaints vexatious and opportunistic.

It is understood five complaints had previously been made about Mr Gormley’s conduct to the Scottish Police Authority (SPA), which oversees Police Scotland, three of which were deemed serious enough to be referred to the Pirc, prompting full-blown investigations.

The latest referral is understood to involve a new, sixth complaint against Mr Gormley.

The Pirc said it would assess the allegation “to determine whether the conduct, if proved, would amount to misconduct, gross misconduct or neither and to establish whether an investigation is required”.

The SPA is next due to review whether Mr Gormley can return from leave on January 25.

He almost returned to duty in November, but Justice Secretary Michael Matheson intervened and the SPA board, which initially agreed to a reinstatement, reversed its decision.

The SPA said its referral to the Pirc followed an assessment which determined that, if proven, the allegations would amount to misconduct and require to be investigated.

Former Justice Secretary Kenneth MacAskill has urged Mr Gormley, the Chief Constable since January 2016, to leave and make way for his deputy, Iain Livingstone.

On Tuesday, Mr Livingstone attacked the SPA's conduct in relation to Mr Gormley's aborted return in November.