Scotland's top inspector of policing has failed to give his backing to Scottish Police Authority (SPA) chief executive John Foley.

Mr Foley has come under pressure after criticism in a report from HM Inspectorate of Constabulary in Scotland (HMICS) which identified "dysfunction" at the top of the watchdog.

The inspection also found ''shortcomings'' in his capacity to provide expert advice and support to the board.

Derek Penman, HM Chief Inspector of Constabulary in Scotland, was asked his opinion of Mr Foley at Holyrood's Justice Sub-Committee on Policing.

Green MSP John Finnie said: "Do you have confidence in the chief executive of the Scottish Police Authority?"

Mr Penman responded: "My position around the chief executive is that there needs to be an effective relationship with the chair and they need to have the skill set that's necessary for moving on policing in the new structures.

"I would hope that the recommendation that we have put in place which is to look at the executive structures within the SPA will also look at what skill sets and things are required from that and determine what the best mix of team and staff would be."

Mr Penman said that in fairness to the chief executive, he is "very busy" and "spread very thinly" as a result of staffing issues.

He earlier told Conservative MSP Margaret Mitchell he does not think Mr Foley and outgoing chair Andrew Flanagan had worked well together.

Mr Flanagan announced his resignation last week in advance of the HMICS report looking at serious concerns raised by two Holyrood committees about openness and transparency at the SPA.

But Gill Imery, assistant inspector of constabulary in Scotland, said interviews with board staff had revealed they felt Mr Flanagan's treatment had been "quite unfair" and they viewed the HMICS inspection as "disproportionate" and "not really necessary".

Mr Finnie replied: "I find that very worrying."

Ms Mitchell suggested it was time for the third SPA chair to be appointed by the Scottish Parliament rather than by ministers.

"I suggest to you that it couldn't be any worse than the appointments that seem to have been made so far," she said.

Mr Penman said the appointments process is a matter for the committee and Parliament, adding: "I would agree with you that it's absolutely critical that the right person is recruited into the post of the chair with the right skill sets to take this forward and the selection process to that, I think, would be absolutely critical.

"For me there's a real risk that the continuing focus on the SPA and its weakness in governance will limit opportunities to highlight and indeed probably scrutinise positive developments in policing, I think this has the potential not only to impact negatively on confidence in the SPA but could have an impact more widely on the public's confidence in Police Scotland."

A SPA spokeswoman said: "Mr Penman welcomed and endorsed the review of SPA support and structure announced last week, as does the chief executive of the SPA."