A police helicopter pursued a UFO after almost colliding with it over a military base near Cardiff.

The pilot was forced to bank sharply to avoid being hit by the mystery aircraft as the helicopter was returning to St Athan base, reports the Daily Telegraph.

The crew, who described the UFO as "flying saucer-shaped", gave chase as far as the north Devon coast before they ran low on fuel.

The police aircraft was hovering at 500ft and waiting for clearance to land on June 7, when those onboard spotted the other craft hurtling towards them from below.

A spokesman for South Wales Police said: "We can confirm the Air Support Unit sighted an unusual aircraft. This was reported to the relevant authorities for their investigation."

It was reported that the aircraft closed in at great speed, aiming straight for the helicopter which swerved sharply.

"They are convinced it was a UFO. It sounds far-fetched, but they know what they saw," added the spokesman.