THE watchdog who investigates complaints against the police has revealed her organisation was pushed to the brink after a rash of cases involving senior officers added to its workload.

Kate Frame, the Police Investigations and Review Commissioner (Pirc), said her resources were “stretched to the limit” and she feared the situation had become unsustainable.

In the past six months, the Pirc has launched five misconduct investigations into absentee Chief Constable Phil Gormley, as well as probes into other senior Police Scotland officers.

Around a third of the Pirc’s current 31 cases involve the upper echelons of the force.

It also investigates alleged criminality by officers, deaths in custody and deaths following contact with the police, and other police matters deemed to be in the public interest.

In a letter to Holyrood’s Justice Committee, Ms Frame said the growth in cases had made it “particularly difficult” to investigate matters as quickly as she would have liked.

She said her 30 full-time staff had been under “acute pressure”, with some cases requiring more than 100 witness statements.

She told MSPs: “Throughout 2017, I continued to witness an increase in the scale and complexity of investigations referred to me and a considerable rise in the number of senior officer [above of Assistant Chief Constable rank] misconduct referrals to me by the Scottish Police Authority.

“Being aware that our resources were already stretched to the limit and as I was extremely concerned about the unsustainability of the situation, I raised this issue on several occasions with our Sponsor Team at the Scottish Government.”

She said in November she was offered a one-off £100,000 addition to her budget for 2017-18, and last week was “further heartened” by £1,068,000 by being added to her budget, which “meets the current business demands of the Pirc”.

LibDem MSP Liam McArthur said the Pirc's investigations had been "held back by a lack of resources".

He said: " While the Scottish Government has now given it a fresh financial package, it is clear that Pirc could have done with this much earlier. The police officers and members of the public waiting for news on their cases will be disappointed to learn that the Commission's work has been hampered for the last year."