The Kremlin has vetoed a move to launch a fresh investigation into the death of Yuri Gagarin, the first man in space, despite aviation specialists' belief that they have unravelled one of the 20th century's greatest enigmas.
The rebuff comes as Russians celebrate Cosmonauts' Day today, the anniversary of Gagarin's historic flight around the Earth on 12 April 1961. That foray, which lasted just 68 minutes, was a milestone in the space race between the Soviet Union and the US. But Gagarin was destined to a short, controversial life.
On 27 March 1968, Gagarin died in a mysterious plane crash while on a routine training mission in a MiG-15 with his flight instructor, Vladimir Serugin, just outside Moscow. The results of the official investigation that followed were hypothetical and did not explain exactly what happened and why. Investigators were only able to conclude that "the most probable cause" of his death was a sudden inflight manoeuvre that sent the MiG into a nosedive from which it was impossible to recover.
They suggested that the pilots had been forced to swerve sharply to avoid a collision with a weather balloon or to avoid cloud cover.
The vague nature of the commission's findings led some experts to question Gagarin's competence as a pilot and created an information vacuum that has since spawned endless conspiracy theories.
One of the most insulting has the two men drunk on vodka, and losing control of the plane. Gagarin found fame hard to deal with after his return from space, it is argued, and had become a heavy drinker.
Other theories have been no less far-fetched: that he was abducted by aliens, that he survived the crash and died in a Soviet psychiatric ward in 1990, that Serugin killed them both because he was jealous of Gagarin, or that Gagarin staged his own death, had plastic surgery and disappeared.
There have also been suggestions that the "accident" was arranged by the Soviet leader at the time, Leonid Brezhnev, who apparently felt threatened by Gagarin's fame and was embarrassed by his alcohol- fuelled philandering.
But Igor Kuznetsov, an aviation engineer involved in the 1968 investigation, thinks that he and his colleagues have solved the enigma after conducting their own investigation using modern methodology.
In an interview with The Independent, he said he was convinced that Gagarin and Serugin died in a tragic accident and argued that the doomed plane's final movements differed radically from what had previously been thought. …