An MP conducting an investigation into the death of Dr David Kelly said last night he believed his computer files have been wiped.

Lewes MP Norman Baker said he has evidence to prove Dr Kelly did not die as a result of suicide.

The Liberal Democrat believes computer files at his Lewes constituency office have been remotely wiped.

The MP said he had gathered evidence which showed it was "clinically impossible" for Dr Kelly to have died in the way that was claimed.

He said: "What my investigations to date have demonstrated is that there are significant medical doubts from experts and professional medical people about the alleged cause of death.

"Indeed there are a number of specialist medical experts who tell me that it is clinically impossible for Dr David Kelly to have died the way that was described. I am suggesting the explanation for suicide simply doesn't add up."

Dr Kelly was the Ministry of Defence scientist whose conversations with a BBC journalist led to reports that the Government had "sexed up" the threat posed by Iraq's weapons of mass destruction.

In July 2003, nine days after being named in press reports as the possible source for the BBC story, Dr Kelly was found dead with slashed wrists on land close to his Oxfordshire home.

In May, Mr Baker said he gave up his front bench role to investigate "unanswered questions" about the death of the weapons scientist.

Mr Baker said he has contacted an Assistant Chief Constable of Sussex Police about the computer files. But last night Sussex Police were unable to confirm his complaint. A spokesman said: "There is nothing on the system at the moment. I can't confirm or deny anything."