AIRPORT security failed to detect a seven-inch chef's knife in the hand luggage of Worcestershire TV celebrity chef Alan Coxon as he travelled the world for six months.

Mr Coxon of North Littleton, near Evesham, thought he had lost the knife 12 months ago when he was appearing on Open House with Gloria Hunniford. It was discovered by security staff at Geneva airport as he was returning from a filming trip last week.

Over the previous six months, Mr Coxon flew in and out of Geneva six times from Heathrow and Gatwick, and Heathrow to Johannesburg a number of times without the lost knife showing up on X-ray machines.

Mr Coxon - known for his appearances on Good Food Live and BBC2's Ever Wondered About Food? - was travelling with a TV crew when a woman on a security desk at Geneva airport said she thought he had a knife in his hand luggage.

"I was not aware it was there", Mr Coxon said. "My hand luggage, on a small trolley, was emptied out and nothing found.

Again the X-ray indicated the knife was there and it was actually found, along with a CD ROM, behind a piece of cardboard.

"I thought I was going to be arrested with the TV crew looking on. The woman was actually very nice about it, but of course she would not let me take it on the flight, and so I told her to keep it."

Mr Coxon said the searches and explanations took so much time he only managed to get on the plane with two minutes to spare.

"I am always pleased that security checks are carried out," Mr Coxon said, "But it is quite frightening to think that such a big blade went through security checks undetected so many times."

A spokesman for Heathrow Airport said the would investigate the security breach.

"We would encourage any passenger who inadvertently carried a sharp item through security to report it," he said.