Former Strathclyde Police chief constable Sir John Orr has died, it has been announced.

His death at the age of 72 was revealed in a statement from Kilmarnock Football Club, where Sir John was an honorary president and a former chairman.

Sir John was at the helm of what was then Scotland's largest police force from 1996 until 2001.

He was knighted by the Queen in 2001 for services to policing, following a career which saw him head the Lockerbie bombing investigation.

Sir John was already joint head of CID in Strathclyde Police with the rank of detective chief superintendent.

He arrived at Lockerbie in the early hours of the fateful morning having been seconded at the request of the then Chief Constable of Dumfries and Galloway Police.

He held that job for two years, blending together a team of officers from different forces into a unit that eventually succeeded in producing evidence from the most unpromising circumstances imaginable.

Sir John served as chairman of Kilmarnock FC between 2001 and 2003 following what the club described as a "distinguished" career in the police service.

In 2004, he was appointed as an independent expert to review procedures for authorising marches and parades.

His 300-page report, which proposed new moves to give councils greater control over parades, was published in January the following year.

The football club said in a statement on Monday: "Everyone at Kilmarnock Football Club is deeply saddened to hear of the passing of honorary president and former chairman Sir John Orr.

"Our thoughts are with Sir John's family at this difficult time."

Ray Montgomerie, who captained Kilmarnock to the Scottish Cup in 1997, tweeted: "I am so so sad to hear about the passing away of my dear friend Sir John Orr.

"Our ex chairman here at Rugby Park and a former chief constable of Strathclyde Police. A great Killie man with morals and principles. My heartfelt thoughts to all his family."

Strathclyde Police was one of eight regional forces that merged in 2013 to form Scotland's national force, Police Scotland.

Deputy Chief Constable Iain Livingstone said: "I am deeply saddened to hear of the death of Sir John Orr, the former chief constable of Strathclyde Police.

"Many people at Police Scotland had the privilege of working with him during their careers and he will be remembered as a first class police officer and an absolute gentleman. My thoughts are with his family at this sad time."