Six doctors are taking legal action to demand that the inquest into the death of weapons expert David Kelly is reopened because there is not enough evidence to prove he committed suicide.
The Government scientist's death was investigated by Lord Hutton, who concluded that he bled to death as a result of a cut to his wrist and an overdose of painkillers.
But Michael Powers QC, a former assistant coroner, said the cuts would not have caused him to bleed to death and that there was only a normal dose of co-proxamol present in Dr Kelly's body.
He said that for a coroner to reach a verdict of suicide there must be evidence "beyond reasonable doubt" that they intended to kill themselves.
Dr Powers, an expert in coroners' law, said: "Suicide cannot be presumed it has to be proven. From the evidence that we have as to the circumstances of his death, in particular the aspect of haemorrhage, we do not believe that there was sufficient evidence to prove beyond reasonable doubt that he killed himself."
He said that there was not enough information to determine whether Dr Kelly was murdered or killed himself.
There was a rush to get an answer as to what had happened and the inquest should not have been left to Lord Hutton, who is not a coroner, Dr Powers said.
He went on: "There are many times in political life that the country needs to have an answer and the desire to have an answer overwhelms the desire to get the right answer. There is that pressure to find a conclusion.
"I have no doubt that many of us when we read about this thought that he had killed himself. But you cannot be certain.
"Everyone's death is significant. This death had a significance which was greater and I feel that the process of the investigation of death ought to have been a thorough one. That was not provided for him."
