Northern Ireland's police chief has said a probe into alleged misconduct in public office has completely vindicated him.

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

Michael Maguire's probe examined how the PSNI handled a bribery inquiry into the awarding of a contract to supply vehicles to the force.

Mr Hamilton said he, Deputy Chief Constable Drew Harris and other PSNI officers subject to the Police Ombudsman of Northern Ireland probe had been exonerated.

"56 allegations made - not one of them upheld, no recommendations for any criminal or misconduct proceedings," he said.

"Our actions have been completely vindicated and we have been exonerated."

Former West Yorkshire chief constable Mark Gilmore, an ex-PSNI officer, and retired PSNI assistant chief constable Duncan McCausland were among nine people interviewed by detectives in the 2014 police 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.

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

It is understood their claims included allegations that police documents were altered.

Mr Hamilton, Mr Harris and current Assistant Chief Constable Mark Hamilton were all investigated by the ombudsman.

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

Mr Hamilton told the BBC that he was "relieved but not surprised" that the probe had cleared them all.

"I had confidence in our actions, that we had acted with integrity, that the original investigation into these bribery and corruption issues was done professionally, was done to high investigative standards, and that has been borne out in the Police Ombudsman's report," he said.

"The investigation into 56 allegations against senior officers has fully exonerated every officer on every allegation."

The Ombudsman's Office had treated the investigation as a "critical incident."

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

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.

At the time of his initial suspension in June 2014, Mr Gilmore, who attended a police interview in Belfast voluntarily, insisted he had always acted with honesty and integrity.