EXCLUSIVE

ALLEGATIONS that one of Scotland's top police chiefs failed to carry out staff appraisals have been referred to the Crown Office.

Assistant chief constable Ruaraidh Nicolson has been accused by fellow officer Michael Orr of not providing the correct paperwork in relation to staff performance.

The complaint has been forwarded by the Scottish Police Authority to the country's prosecutors.

The internal row can be traced to the old Strathclyde Police force's investigation into the murder of gangland enforcer Kevin Carroll in 2010.

Orr, a detective superintendent, was put in charge of Operation Trilby and interviewed corrupt officer Derek McLeod as part of the probe.

However, Orr found himself at the centre of allegations that inducements had been made to McLeod for him to co-operate with the inquiry.

The Crown Office requested a review of Trilby, including Orr's contact with McLeod, an exercise overseen by Nicolson.

The same chief officer, who rose to temporary deputy chief constable at Strathclyde before becoming an ACC at Police Scotland, also conducted a criminal inquiry into Orr.

However, the investigation was dropped and no proceedings were ever launched.

Orr then made a series of complaints against Nicolson - including that the senior officer did not complete appraisals for him between 2005 and 2010 - that were investigated by the Police Investigations and Review Commissioner (PIRC).

In its report, PIRC concluded that it "appears" Nicolson "did not complete appraisals for the majority of superintendents for whom he was line manager".

It added that, in relation to the lack of appraisals for the detective superintendent, Orr must also "share responsibility" for this omission.

Last February, the SPA responded by saying that its chair would write to Police Scotland about "performance related matters" relating to Nicolson.

However, Orr has made a fresh complaint to the SPA about PIRC's finding that Nicolson appeared not to have completed appraisals for numerous officers.

The watchdog forwarded the complaint to the Crown and it is understood the ACC has been informed of the matter.

An SPA spokesperson said the watchdog's complaint handling process meant that allegations are referred to the Crown.

She added: "Also, if we receive a complaint against a senior officer we would, as part of our process, advise them of the complaint. We are unable to comment further."

A Crown Office spokesperson said: "COPFS do not comment on the identity of individuals who may be the subject of investigations."

Police Scotland, Nicolson and Orr all declined to comment.