There is "no hard evidence" government files have been shredded ahead of new openness laws, a watchdog has said.
Government departments say they are following rules on public records
The Tories had claimed systematic shredding was under way before the Freedom of Information Act's implementation on Saturday.
Information commissioner Richard Thomas denied this on BBC's Today programme.
But Shadow Cabinet Office minister Julian Lewis reiterated his demands for Mr Thomas to consider his position and described him as a "lap dog".
Mr Thomas said: "If anyone is suggesting that files are being deliberately destroyed in order to avoid disclosure under the Act, well, as from tomorrow it becomes a criminal offence to do that.
"I have seen no hard evidence of that going on."
Figures compiled by the Tories suggested civil servants had drastically stepped up the shredding of official documents ahead of the Act.
But Mr Thomas, who will decide whether it is right to continue to withhold some information, insisted there would be "no hiding behind exemptions".
Cabinet ministers will only be able to prevent publication "in the most extraordinary circumstances", the commissioner said.
"Our job is to be the independent, I hope robust, referee to decide whether or not in a particular case," he told Today.
But Mr Lewis, who has previously denounced Mr Thomas, called on him to consider his position.
"This man appears to be more of a lap-dog than a watchdog of the government," he said.
He added: "I find his attitude as astonishing as it is disturbing.
"Of course he has found no hard evidence, because he has not had the opportunity to investigate what's going on.
"He is like a judge who is new to his job and determined to see, hear and find no evil."
Dr Lewis, who is the Conservative spokesman for the Cabinet Office, said the fact there had been a huge increase in the number of files being destroyed was prima facie evidence that "something sinister" was
Dr Lewis previously said he had discovered a huge acceleration in shredding from a series of parliamentary answers.
He said it was Mr Thomas's job to examine that evidence.
"If he is not prepared to do that, he ought to make way for someone who is," he said.
The Freedom of Information Act will cover England, Wales and Northern Ireland from 1 January although it will not come into effect until Tuesday, which is the first working day.
Similar measures are being brought in at the same time in Scotland.
It provides the public with a right of access to information held by about 100,000 public bodies, subject to various exemptions.