Two paramedics who attended the scene where weapons expert David Kelly was found dead have expressed surprise at the official inquiry's conclusion.
The Hutton inquiry concluded Dr Kelly died of wounds to his left wrist
The Hutton Inquiry found he died as a result of a slit wrist in July 2003.
But the medics said the small amount of blood they saw around the body was inconsistent with the cut on his wrist being the cause of death.
They spoke to the inquiry and Thames Valley Police, who say the investigation will not be reopened.
The scientist killed himself after being named as the possible source of a BBC story.
The story, which claimed that the government had "sexed-up" a dossier on Saddam Hussein's weapons of mass destruction, led to the weapons inspector being subjected to intense pressure.
Paramedic Vanessa Hunt told the Observer newspaper on Sunday: "I just think it is incredibly unlikely that he died from the wrist wound we saw."
Dr Kelly was found dead near his Oxfordshire home in July 2003
The pair gave a press conference after renewed media interest was sparked by the article.
Fellow paramedic Dave Bartlett said: "Everyone was surprised at the outcome [of the Hutton Inquiry].
"I would have thought there would have been more blood over the body if someone had bled to death."
He added that the pair's observations of the scene "were inconsistent with the conclusion of the Hutton Inquiry".
"We stress that is our personal opinion. We do not represent the views of any body or group."
'Lack of blood'
Explaining her belief that the wound on Dr Kelly's wrist did not cause his death, Ms Hunt said: "There just wasn't a lot of blood.
"When someone cuts an artery, whether accidentally or intentionally, the blood pumps everywhere."
The pair are not the only ones to question the inquiry's findings.
A team of scientists calling themselves the Kelly Investigation Group also believe there would have been much more blood at the scene.
But Dr Bob Van Hegan, a consultant pathologist, disagrees with the paramedics' assessment.
He told Sky News that in addition to the wrist wound there were three further factors which could have contributed to the scientist's death.
Dr Van Hegan pointed out that Dr Kelly's coronary arteries were in a poor condition, he suffered from a vascular disease and he had taken an opiate drug.
Tom Mangold, a former BBC journalist and friend of Dr Kelly, said: "The fact that the paramedics did not find sufficient blood does not mean that it was not spilt.
"Although I am sure they are speaking in good faith there is no doubt in my mind, or anyone else connected with the case, that David committed suicide."
In March Oxfordshire coroner Nicholas Gardiner decided not to reconvene the inquest into Dr Kelly's death after it was adjourned while Lord Hutton held his inquiry.
The inquiry, which concluded that the weapons expert committed suicide, was deemed to remove the need for a full inquest.
A spokesman for Thames Valley Police said on Sunday: "[We] are fully satisfied with the outcome of the investigation into David Kelly's death. "