A 46-year-old man questioned late last year by detectives investigating the £53 million Securitas robbery is still missing from home.

Detectives have issued a new appeal over the disappearance of Sean Lupton who vanished from his home in Hillside Road, Whitstable, on December 12.

Police say Mr Lupton did not make contact with his family or friends over Christmas and New Year.

Det Insp Tony Hubbard said: “We are increasingly concerned about Mr Lupton and we believe that it is out of character for him not to have contacted his family over the holiday period.”

Mr Lupton’s white van has been found in Aycliffe, near Dover. The Ford Transit van was discovered shortly after an initial police appeal on December 19. It was parked and locked up at the side of the road near the junction of St David’s Avenue and St Patrick’s Avenue.

Police are considering the possibility that he may have got on ferry to France and have appealed to anyone crossing the Channel since December 12 2006 to try and remember whether they saw Mr Lupton. Posters have been circulated at the ort and in the Dover area.

Mr Lupton, a builder who is married with two teenage children, was last seen in Capel le Ferne, near Folkestone, at 6pm on Tuesday, December 12.

He is well known in boxing circles in the south east and has trained youngsters at the Herne Bay boxing club.

Anyone with information is asked to contact the police incident room on 01227 868321 or Crimestoppers 0800 555 111.