The Ministry of Defence has side-stepped claims that a West Wales RAF base plays a secret role probing UFOs.

Gower MP Martin Caton has been pressing the Government over activities at the base at Brawdy, Pembrokeshire, in a series of Commons questions.

He quizzed the MoD over whether RAF Brawdy was used to investigate unidentified flying objects.

The MP also asked whether it still used an underwater sound surveillance system set up to listen for hostile submarines.

Suspicions about the base have surfaced as an international panel of scientists called for a full-scale investigation into sightings.

Ten leading experts from America, France and Germany have criticised scientists for paying too little interest in UFOs despite scores of mysterious incidents.

A massive disc reported in the skies above Paris by the crew of a military aircraft four years ago is among sightings which deserve further inquiry, said the panel led by Dr David Sturrock, of Stanford University, California.

But yesterday MoD minister said British forces only investigated UFOs if they feared a military threat.

MP John Sellar said: "Unless a report reveals evidence of a potential threat from an external military source no attempt is made to determine the precise nature of what might have been seen.''

He added that the Pembrokeshire base had been handed from the RAF to the Army two years ago but failed to say whether it had ever investigated UFO sightings.

Today Mr Caton played down his interest in the extra-terrestrial, saying he had asked the Commons questions on Brawdy for a constituent.

"I personally think it's very unlikely and it is not something I have a great understanding of or interest in.

"But I have to admit one of my favourite films is Close Encounters of the Third Kind.''