THE Polish government is to demand access to classified British documents as part of criminal investigation into the death of the country's wartime leader.
A resolution passed by the Polish parliament, which obliges the government to ask for the secret files, called on Britain to "as quickly as possible declassify and grant access to any documents relating to the circumstances surrounding the death of General Wladyslaw Sikorski".
The general, who was the Polish prime minister and commander-in-chief, died when his RAF Liberator crashed into the sea seconds after taking off from Gibraltar in July 1943.
Despite a British wartime inquiry attributing the cause of the crash to a technical malfunction, speculation has abounded for decades that the Polish leader was assassinated.
The conspiracy theories have been fuelled by certain British files relating to the case remaining top-secret, although 65 years have passed since the tragedy.
"Without those documents we will never get the whole truth into the death of Gen Sikorski," said Zbigniew Girzynski, a Polish MP who has spearheaded the campaign to get access.
Earlier this year, Poland launched a criminal investigation into the accident, and last week experts exhumed the general's body from a crypt in Krakow's cathedral to ascertain whether he died by accident or was murdered.
Some historians argue that Gen Sikorski could have been killed by either Britain or the Soviet Union, both of whom may have seen his demands for Polish rights and independence as an unwanted impediment to good relations between the allies.
Historians point to the fact that the general had been the subject of two assassination attempts, both involving his aircraft, before his visit to Gibraltar, and that many mysteries surround the fatal crash.
The Czech pilot, the sole survivor, was found wearing his Mae West lifejacket – despite it being known that he habitually never wore one – and the plane had waited an unusual length of time at the far end of the run way before it began its take off.
At Gibraltar, due to the special treatment accorded to VIPs, there was uncertainty about who had boarded the plane and its cargo – and thus the identity of the bodies recovered.
The body of Sikorski's daughter, Zofia, was never found, and there were reports in 1945 that she was spotted in a Soviet Gulag by a member of the elite Polish commandos.
By 2000, only a few British intelligence documents relating to Gen Sikorski's death had been declassified. The majority are to remain secret for the next 50 to 100 years.
One recently declassified briefing paper was dated 24 January, 1969, to the British Cabinet Secretary, Sir Burke Trend, from Sir Robin Cooper, a former pilot employed in the Cabinet Office.
After reviewing the wartime inquiry's findings, he wrote: "Security at Gibraltar was casual, and a number of opportunities for sabotage arose while the aircraft was there."
Although Sir Robin doubted sabotage had taken place, or that the pilot had crashed the aircraft deliberately, he went on to add: "The possibility of Sikorski's murder by the British is excluded from this paper. The possibility of his murder by persons unknown cannot be so excluded."
The crash of the Liberator is portrayed in the 1958 film The Silent Enemy, in which the team of divers charged with retrieving his briefcase from the wreck is led by Lionel "Buster" Crabb, himself later to disappear in 1956 in mysterious circumstances while diving in the vicinity of a visiting Soviet warship.
In 1968 Soldiers, a play by a German writer staged in London, alleged that Winston Churchill had been in on the plot.
• General Wladyslaw Sikorski wanted to be buried in a "free Poland".
• When he died in a plane crash off Gibraltar in 1943, aged 62, his body was flown to Britain and buried in a Polish war cemetery in Newark, Nottinghamshire, along with 500 comrades.
• His remains were repatriated in 1993 when hundreds of Polish and British servicemen attended a requiem mass. The cortege travelled to the RAF base, where the coffin, draped with the Polish flag, was put on a horse-drawn carriage.
He was laid to rest in a tomb in Wawel Cathedral in his native Krakow.