Police in Britain have called for Interpol assistance to trace a sports fan who has not returned home from the Olympic Games, a force spokesman said today.

Melvyn Gamblin, 37, of Darlington, County Durham, regularly sent texts and emails to his family throughout the Athens Games, but they have not heard from him for almost a month.

In his last message on August 28, he told them of his joy after witnessing Great Britain's unexpected 4x100m relay gold.

Mr Gamblin, who suffers from ME, was due to fly back to Luton Airport on September 3, before spending time in London and Manchester.

But records show he did not take his easyJet flight and, although hotel staff in Athens reported seeing him leave, he did not officially check out and left some items in his room.

Mr Gamblin, who used to work for the Environment Agency and ICI, is originally from Bristol where his parents still live. He has sisters, Bridget and Rachel, and a brother, Bryan, who lives in Edinburgh.

Mr Gamblin, known to friends as Melv, loves sports, and was in Australia for England's rugby World Cup win. He is also a keen supporter of Middlesbrough FC.

Bryan said: ''We are all worried sick about him because he is a very organised, detailed person who always plans well ahead. ''This is totally out of character and we cannot think what has happened to him.

''It is hard to believe he would miss Middlesbrough's first ever European match.''

His family alerted the authorities a week ago and Durham Police have liaised with Interpol, Greek officials and the Foreign Office.

If anyone has been in contact with him, they are asked to telephone police in Darlington on 01325 467681.