Shadow health secretary Andy Burnham denied putting pressure on the health watchdog to play down concerns over a scandal-hit hospital trust where mothers and babies died.
The Care Quality Commission (CQC) has been under fire over allegations it covered up its failures over investigations into the Morecambe Bay trust.
The Sunday Telegraph said it had seen a cache of documents which revealed the CQC was intent on suppressing negative publicity and was under pressure from Labour ministers in the run-up to the 2010 election.
But Burnham, who was health secretary at the time, said he denied the central allegation that he put pressure on the CQC to cover-up information about Morecambe Bay, saying it was "fundamentally disproved" by the decisions he took to actively identify problems at hospitals during his time in office.
He said he had "no immediate recollection" of having conversations about Morecambe Bay at the time but that the issues may have been raised in a "general meeting".
Burnham said the Government had questions to answer over the suppression of the CQC report into Morecambe Bay.
He told Sky News's Murnaghan programme on Sunday: "I never said to the CQC 'don't say that, do say the other'.
"That wasn't my role, they were an independent regulator.
"Obviously we had discussions about problems that were in the NHS, we had a discussion about Basildon hospital and it was at that point that I said we needed to have a system that could provide the reassurance that people needed and also where there were problems for them to be brought out.
"The central allegation that I was kind of in that period trying to say don't do anything, don't say anything, don't bring any problems out, keep them all hidden, is fundamentally disproved by the decisions I took in relation to the expediting the registration of hospitals."
Asked why he told Morecambe and Lunesdale's Tory MP David Morris that he had no recollection of discussions about Morecambe Bay, Burnham said: "I didn't want to provide wrong information.
"I don't hold all the paperwork from that period.
"When you are Secretary of State for Health many issues are being raised with you on a daily basis.
"Lots of papers are coming across your desk.
"I don't have any recollection of it, I don't think a specific concern was put to me about Morecambe Bay.
"That's why I have said that clearly to David Morris but I haven't reviewed all the paperwork held by the Department of Health."
He went on: "I don't know whether concerns were raised as part of a more general meeting and I would have to review all the paperwork to provide that reassurance.
"But I'm prepared to do that.
"What you're not saying here is that this cover-up, the deletion of the report, happened on this Government's watch, not on our watch."
He added: "I do think you need to be putting some of these questions to the current Government.
"We know that the whistleblower went to the last Secretary of State with concerns, what action was taken on those concerns?"
Meanwhile, a whistleblower has claimed he was forced out of a senior role at the CQC.
Roger Davidson lost his job as head of media and public affairs for the CQC just before the 2010 general election after revealing how a quarter of NHS trusts failed to meet basic hygiene standards.
The Sunday Telegraph said he was forced to sign a gagging order when he left and was told that the CQC was "railing against" his action to "highlight issues".
Davidson gave evidence under oath to the Francis Inquiry into failures at Mid Staffordshire NHS Foundation Trust which led to up to 1,200 deaths, where he said it was made clear to him that the CQC should not "make too much noise" about problems in the NHS.
In addition, a senior NHS official is facing calls to resign over links to Morecambe Bay.
Mike Farrar, who heads the body representing NHS trusts, was in charge of North West Strategic Health Authority (NWSHA) at the time of the failings.
The Parliamentary and Health Service Ombudsman (PHSO) confirmed it was investigating complaints against the NWSHA.
James Titcombe, whose nine-day-old son Joshua died at Furness General Hospital, said Farrar should consider his position as chief executive of the NHS Confederation.
He told the Independent on Sunday: "There was a failure, in my opinion, of the NWSHA in its duty with midwifery supervision.
That was a serious failure that is being investigated.
"The whole role of the SHA has been highlighted as dysfunctional.
"I think (Farrar) should consider his position. He has always said the buck must stop with managers. But he has never taken responsibility for his role at the SHA."
A PHSO spokeswoman confirmed the NWSHA was being investigated, but said the watchdog focuses on organisations not individuals.
Michael O'Higgins, chairman of the NHS Confederation, said it was a "routine" inquiry into the organisation, not an individual.
"If a chief executive stood down every time there was a complaint about his or her organisation, and not about them personally, it would not make sense," he said.
"There is no reason for the chief executive of the NHS Confederation to stand aside while this inquiry takes place."