The Prime Minister's car was not the cause of a plane's crash landing at Heathrow in January investigators say.

It had been suggested radio signals from Gordon Brown's motorcade interfered with the plane causing it to land short of the runway narrowly missing a busy road and leaving massive skidmarks in the grass.

The plane, which had travelled from China, was carrying 136 passengers and 16 members of crew.

Only one person was seriously hurt.

The stricken plane pulled up around 1,000 meters from the aircraft about to take Mr Brown to Beijing for an official visit.

An investigators' report has ruled out electromagnetic interference, but states the cause of the crash is unknown.

However investigators did find that engines had low pressure at the inlet to fuel pumps.