Nearly a quarter surveyed believe Dr David Kelly did not commit suicide - BBC poll
Almost one in four, 23%, of people said they believed the Government scientist Dr David Kelly did not commit suicide when asked in an opinion poll for BBC Two series The Conspiracy Files.
Thirty nine per cent believed that he did commit suicide and 39% said they did not know.
The poll, conducted by GfK NOP for the BBC, comes ahead of a three-part BBC Two series The Conspiracy Files, starting on Sunday 18 February, investigating conspiracy theories that have entered mainstream public thinking.
The death of Dr David Kelly
In July 2003, the body of Dr Kelly, Britain's leading expert on biological weapons and a key UN Inspector in the hunt for Saddam Hussein's Weapons of Mass Destruction, was found on Harrowdown Hill in Oxfordshire.
The official account given by the Hutton Inquiry says that under pressure he committed suicide by cutting his left wrist, and taking an overdose of the painkiller Co-Proxamol.
9/11 World Trade Center attacks
There was less support for allegations that the United States government was involved in a wider conspiracy to carry out the 9/11 attacks on the World Trade Center and the Pentagon.
Sixteen per cent of people polled believed the US government was involved in a wider conspiracy.
Sixty-four per cent of those questioned believed there was not a wider conspiracy.
The rest said they did not know.
9/11: The Conspiracy Files features among others Dylan Avery, producer of film Loose Change.
His film has been watched by tens of millions of people on the internet and is due for a cinematic release. It claims that 9/11 was a strike by the US government on home soil.
The death of Princess Diana
Prior to Lord Stevens report in December 2006, there was also significant public support for the theory that Princess Diana's fatal car crash was not an accident, the opinion poll suggests.
Nearly a third, 31%, believed Princess Diana's death was not an accident.
Forty-three per cent of people agreed it was an accident, with 27% saying they did not know.
An investigation by the French authorities concluded it was an accident and the driver of Diana's car had been drunk and driving too fast.
BBC Two's The Conspiracy Files starts on Sunday 18 February 2007 at 9pm, investigating the theories surrounding the events of 9/11.