The first stage of an official inquiry into the death of the British weapons expert, Dr David Kelly, opened in London today.
Lord Hutton has said he intends to call the Prime Minister, Tony Blair, and the Defence Secretary, Geoff Hoon, to give evidence.
Andrew Gilligan, the BBC journalist who cited Dr Kelly as a source, will also be called to testify.
Dr Kelly had been at the centre of a row between the British government and the BBC over claims about Iraq's weapons capability.
At today's hearing, Lord Hutton explained how he intends to conduct the investigation into the scientist's apparent suicide.
Lord Hutton, a former Lord Chief Justice in Northern Ireland, has said most of the enquiry will take place in public.
He will not be able to compel witnesses to testify.
The inquiry is expected to be put on hold until after Dr Kelly's funeral, which will take place next Wednesday near his home in Oxfordshire.

