Top cop hits out at corruption watchdog

An inquiry into alleged police misconduct could have been completed months ago if internal investigators had been involved instead of the corruption watchdog, the police commissioner says.

A former policeman has been the subject of a Corruption and Crime Commission investigation over allegations he punched and kneed a prisoner in the head at the Broome watch house earlier this year.

WA Police Commissioner Karl O'Callaghan served a loss-of-confidence notice on the First Class Constable in May, forcing him to stand down.

He told reporters on Tuesday that the matter could have easily been resolved by now by internal investigators.

Mr O'Callaghan also took a swipe at the CCC for recently complaining that police won't participate in voluntary interviews.

"They don't have a choice if the internal investigators do it, so we've got the power," he said.

The commissioner made the comments after being quizzed by a parliamentary committee conducting an inquiry into custodial arrangements at police lock-ups.

Mr O'Callaghan said the CCC's time would be better served looking at "more serious" matters.