RAF asked for help to investigate death of Poland's wartime leader

Polish prosecutors have asked the RAF for documents as they try to unravel the mystery surrounding the death of the country's wartime leader.

Investigators want the technical details of the model of RAF Liberator bomber that crashed into the sea shortly after taking off from Gibraltar in 1943, killing General Wladyslaw Sikorski, then Poland's prime minister and commander-in-chief.

The general's death has long been the subject of speculation, with claims he was assassinated on the orders of Stalin, or even Churchill, to remove an impediment to Anglo-Soviet relations.

"To find out if the aircraft was sabotaged we need the opinion of aviation experts, so therefore we need the documents on the Liberator," said Dariusz Psiuk, a prosecutor from Poland's Institute of National Remembrance, the body charged with investigating crimes committed during the war and during the communist period.

While most historians have ruled out the possibility the general died before the crash they are still exploring the hypothesis that his aircraft was sabotaged.