POLICE say the reason why the deputy head of Durham School went missing remains a mystery at this point.

A major search is continuing on the East Durham coast for father-of-three Mark Bushnell, who has been a popular and respected member of the school for more than 20 years.

He left home in Durham City on Sunday morning to take some washing to a laundrette, but his car was later found at a picnic site  at Blackhall Rocks.

Police revealed today (Tuesday, March 11) that a member of the public, answering police appeals for sightings, said he had seen the 50-year-old in that area.

Chief Insp Andy Huddleston, of Durham Police, told a press conference at the school in Durham City: “There is no significant event to say this is the reason he has left home.”

He added that the apparent lack of an explanation for the disappearance was heightening concern for Mr Bushnell’s well-being.

Mr Bushnell was last seen driving a grey Citroen C3.

The car was found in the early hours of this morning (Monday, March 10) at a picnic site near Blackhall Rocks, near Peterlee, East Durham.

Mr Bushnell is described as white, around 5ft 10ins tall, of slim build, with closely shaved grey hair. He may have been wearing a checked shirt and brown or blue jeans.

Speaking on Monday, Headmaster of Durham School, Martin George, said everyone was concerned for Mr Bushnell.

He said: "Mark is a highly-respected colleague and friend at Durham School.

"As deputy head he constantly works for the benefit of pupils.

"The whole school community is deeply concerned for his welfare and would urge him to contact his family as a matter of urgency.

"We would also ask any members of the public who may have seen Mark to contact police immediately."

Mr Bushnell, who teaches economics, became deputy head in September 2012 and was previously head of boarding.

He has also been the house master of Ferens House and before that Poole House.

Anyone with information on Mr Bushnell's whereabouts, or anyone who may have seen him, is asked to contact Durham Police on the non-emergency number, 101.