THE sense of crisis enveloping Police Scotland has deepened, after more misconduct allegations were levelled at one of its most senior officers.

The Police and Investigations Review Commissioner (Pirc) confirmed it was examining two fresh complaints against Assistant Chief Constable Bernard Higgins.

The Pirc is already conducting two investigations into ACC Higgins, who was suspended in November, and denies any wrongdoing.

The existing investigations concern allegations of misconduct and criminality, including using a police firing range for unauthorised purposes, while the new allegations involve misconduct and gross misconduct.

Both the new complaints were made anonymously to the Pirc, who referred them last month to the Police Scotland’s oversight body, the Scottish Police Authority.

After an initial assessment of their seriousness, the Authority has now referred them back to the Pirc, who will determine whether they merit full-blown investigations.

Earlier this week the Pirc received a fourth complaint regarding Chief Constable Phil Gormley, who has been on special leave since September amid bullying claims.

He is already the subject of three Pirc probes into alleged misconduct, which he denies.

The problems swirling around the single force dominated First Minister’s Questions, with Nicola Sturgeon accused of presiding over a “fiasco”.

A spokesman for Mr Higgins said: "ACC Higgins has been the subject of a campaign of malicious anonymous complaints for many years. 

"All of the anonymous complaints have been investigated and have found to be without merit. 

"The latest anonymous allegations follow that pattern.  Notwithstanding this, ACC Higgins has already provided a full response and denies any wrongdoing."

A spokesman for the Scottish Chief Police Officers Staff Association said: "The Association continue to support ACC Higgins.  There is a pattern of  anonymous complaints particularly in relation to ACC Higgins and we have significant concerns regarding the nature, volume and frequency of these anonymous complaints."