Investigators in Poland say there is no evidence to back up theories that the country's wartime leader, General Wladyslaw Sikorski, was murdered.

The general died when his plane crashed off Gibraltar in 1943, but some of the details of the crash remain unclear.

This has fuelled some people's belief that he may have been killed by the Soviet Union or Britain.

Two months ago, the Polish authorities exhumed the general's body in a bid to clear up the mystery.

But the results of their medical tests have dealt a severe - if not quite fatal - blow to the theory that Gen Sikorski was murdered.