Police in the UK have confirmed that the body found in an Oxfordshire beauty spot matches the description of Dr David Kelly.
Dr Kelly, an adviser on Iraqi arms, had been at the centre of a row about a British government dossier on weapons of mass destruction.
The scientist had denied being the source of a BBC report that the British government doctored intelligence to justify the war in Iraq.
His family had reported him missing last night.
Police said David Kelly, who is 59, went missing from his home in Oxfordshire yesterday afternoon after telling his wife he was going for a walk.
On Tuesday, he was questioned by MPs on a House of Commons Committee about what he told a BBC reporter.
The reporter later filed a report suggesting the government had exaggerated the threat posed by Iraq's weapons of mass destruction.
The British Ministry of Defence has said it intends to hold an independent judicial inquiry if the body found in Oxfordshire is that of Dr Kelly.