The 42-year-old, from Enfield, north London, who is described as "vulnerable", has not been seen since Monday.

His disappearance comes six days after the inquest into the death of his fiancee, Natasha Collins, also a TV presenter, who was found dead in the bath of the flat they shared after taking cocaine and sleeping tablets.

A statement issued on behalf of the Speight and Collins families said: "Mark has not been seen since 1pm on Monday and because of his fragile state of mind, both Mark's family and Natasha's family, as well as all his friends, are deeply worried."

The statement said: "We notified police because of our concerns and we just want to know he is safe. We would urge Mark, if he hears this appeal, to get in touch.

"We don't have any more information at this time. If anyone does have any knowledge as to Mark's whereabouts or has seen Mark in the last 24 hours, please contact Edmonton police station immediately."

The statement was issued outside the home of Carmen Collins, 57, who is Miss Collins' mother. Speight had been living with her since her daughter's death.

As family spokeswoman Amanda Stocks read the statement, a visibly upset Mrs Collins mouthed the words "please get in touch".

A group of reporters, photographers and camera crew had set up camp outside the quiet surburban house in north London.