Northern Ireland’s police chief has insisted a probe into alleged misconduct in public office will not find any wrongdoing.

George Hamilton and a number of other senior Police Service of Northern Ireland officers are subject to the investigation by the region’s Police Ombudsman.

The claims relate to how the PSNI handled an inquiry into the awarding of a contract to supply vehicles to the force.

Mr Hamilton said he is “absolutely confident that there will not be misconduct established”.

And he insisted he has no intention of stepping aside while the probe is ongoing.

Speaking to reporters at an Anti-Slavery Day event in Belfast, he said: “I’m confident in my ability and I have the passion to keep doing this job.

“I’ve got every confidence that the Ombudsman will be able to get on with his job and to investigate the complaints that have been made.”

Former West Yorkshire chief constable Mark Gilmore, a former PSNI officer, and retired PSNI assistant chief constable Duncan McCausland were among nine people interviewed by detectives in the 2014 investigation into bribery and misconduct in public office in relation to the vehicles supply contract.

No charges were ultimately brought against any of the men – all of whom denied any wrongdoing.

Mr Hamilton, current Deputy Chief Constable Drew Harris and current Assistant Chief Constable Mark Hamilton are all now being investigated by Ombudsman Michael Maguire.

PSNI Deputy Chief Constable Drew HarrisDeputy Chief Constable Drew Harris “completely refutes the allegations” (Brian Lawless/PA)

A number of other less senior officers are also under investigation.

Dr Maguire has received complaints from a number of those investigated in the vehicle contracts probe in 2014, including Mr McCausland and Mr Gilmore.

It is understood the claims include allegations that police documents were altered.

Mr Hamilton said however: “I’m absolutely confident that there will not be misconduct established.

“People who made these complaints are entitled to make them and I’d encourage them to have the confidence that I have in the Police Ombudsman and allow him to get on with his job.”

“PSNI can confirm that a number of senior officers, including the Chief Constable and Deputy Chief Constable, have been informed of complaints made against them by former senior PSNI officers,” a PSNI spokeswoman said.

PSNI Assistant Chief Constable Mark Hamilton PSNI Assistant Chief Constable Mark Hamilton is among those being investigated (PA)

“The complaints relate to allegations of misconduct by senior police during a criminal investigation by the PSNI into the two complainants, former senior colleagues, during 2014.

“PSNI acknowledges and supports the need for the Office of the Police Ombudsman to investigate these allegations and all officers are co-operating fully with the investigation.

“The Chief Constable, Deputy Chief Constable and other officers completely refute the allegations made against them and are strongly of the view that these complex investigations into the complainants were conducted with professionalism and integrity.”

The Ombudsman’s Office said its investigation would be treated as a “critical incident”.

Mr Hamilton was appointed chief constable in May 2014 – a month before the investigation into the vehicle contracts became public.

The new Ombudsman’s probe, which was first reported by BBC NI, is expected to extend well into 2018.

Mr Gilmore was suspended from his job in West Yorkshire in the wake of controversy.

He retired two years later having never returned to duty.