THERESA May was aware that there were "tensions" between the former chairwoman of the troubled inquiry into child sex abuse and its panel while she was still home secretary, No 10 has said.
The prime minister is facing calls to "come clean" about the extent of what she knew about the problems at the probe when it was headed up by Dame Lowell Goddard.
Mrs May earlier told MPs there had been "stories" circulating about the former chairwoman but said she could not have intervened on the basis of "suspicion, rumour or hearsay".
No 10 confirmed that Mrs May was still home secretary when she heard about the tensions.
A spokeswoman said: "The stories that she heard were just that there were tensions between the chair and the panel."
Pressed on the issue at Prime Minister's Questions, Mrs May said: "There were stories around about the inquiry and about individuals related to the inquiry, but the home secretary cannot intervene on the basis of suspicion, rumour or hearsay."
She added that as home secretary, she had been aware many of the abuse survivors believed "people in positions of power" had over the years intervened to "stop them getting justice".
On Tuesday the Commons Home Affairs Committee was told that a member of the inquiry panel had privately raised concerns with a director-general in the Home Office in April when Mrs May was still home secretary.
However, Mrs May told MPs: "That conversation was asked to be confidential and it was, as far as I am aware, treated as such.
"I think it is important for us to recognise that, when the Home Office was officially informed of issues, the Home Office acted. It's now for the inquiry to get on and deliver for victims and survivors."
The prime minister's official spokeswoman declined to be drawn on what action the Home Office took, but stressed that, as an independent inquiry, it was first and foremost the responsibility of the panel to deal with the issue.
Labour MP Lisa Nandy, who raised the question with Mrs May in the House, said she must now needed to explain what exactly she had known.
"Theresa May set up the abuse inquiry and appointed its chair. She was the home secretary in April when serious concerns were raised with her department, and only she had the power to act on them," she said.
"Today she suggested that she did know of problems but did nothing at all. For this investigation to regain the trust of survivors the Prime Minister must now come clean about what she knew when, and why she failed to intervene."
Some MPs remain angry that when current home secretary Amber Rudd appeared before committee last month she made no mention of the issues that had been raised, saying simply Dame Lowell had resigned because she was homesick.
The Home Office finally issued a statement last week following press reports about the conduct of Dame Lowell, disclosing that it had been formally contacted by the inquiry on July 29. Six days later the judge resigned.
Dame Lowell has strongly denied allegations against her – including claims that she used racist language – describing them as "falsities", "malicious" and part of a "vicious campaign" against her.
At the committee hearing on Tuesday, MPs were told by members of the inquiry panel that there had been "challenges" working with Dame Lowell.
The new inquiry chairwoman, Professor Alexis Jay, said: "It was clear from the beginning that Lowell Goddard really would have preferred to sit on her own without the assistance of a panel.
"As a consequence of this view that was conveyed to us, we did feel that we were kept at a distance from a lot of the activities of the inquiry."
