STRANGE lights were spotted over a Premiership football ground by a Chesham police officer, newly-released Ministry of Defence files say.

The officer was on duty as Chelsea took on Manchester United in an FA Cup quarter final tie on March 10 1999.

He described seeing four diamond-shaped lights over Stamford Bridge, which he said "moved across the sky fairly quickly, changing shape slowly".

Details of the mysterious incident have been released following a three-year project on UFOs between the Ministry of Defence and the National Archives.

More than 6,000 pages of reports on UFOs were made between 1994 and 2000.

Among the other close encounters reported was a UFO spotted over the home of former Conservative Party leader Michael Howard in 1997.