A POLICE OFFICER may have been on the cusp of being called to give evidence in the trial of a notorious Ayr criminal before he disappeared three years ago.
Senior Sergeant Mick Isles went missing after embarking on a drive from his police station in Ayr to Townsville in September, 2009.
Mr Isle's car, work uniform and a gun were found in dense bushland south of Ayr five days later.
In Brisbane this week, an inquest heard Mr Isles took extended sick leave after he discovered he was under investigation for alleged corruption by the Crime and Misconduct Commission.
Mr Isles eventually was cleared and returned to work in September 2009.
Former district police officer in Townsville Inspector Ian Haughton told the inquest on Tuesday there was a possibility Mr Isles could have been called to give evidence in a court case involving a well-known criminal, referred to only as Galeano.
Insp Haughton said the corruption allegation levelled against Mr Isles stemmed from when police tapped the phone of Galeano and heard him talk about an "in" with a senior cop.
The allegations were to do with Galeano getting a driver's licence, Insp Haughton said.
On the day Ms Isles returned to work, Insp Haughton said he seemed "okay" but appeared uncomfortable when he mentioned the possibility of Mr Isles giving evidence in the Galeano trial.
On the night Mr Isles went missing after he failed to return home from a training seminar in Townsville, Insp Haughton said he ordered an immediate audit of the Isles's family home gun safe.
Mr Isles spent time in Warwick up until 1989 and was a well-respected member of the community.
The inquest continues.