British MPs will grill the Home Office's top civil servant over the resignation of former child sexual abuse inquiry chair Dame Lowell Goddard amid concerns the Government may have covered up allegations about her conduct.
Permanent secretary Mark Sedwill will be questioned at the Commons Home Affairs Committee on Tuesday.
The appearance follows revelations that New Zealander Dame Lowell resigned days after the Home Office was made aware of concerns about her "professionalism and competence".
Home Secretary Amber Rudd and her predecessor Theresa May have now been urged reveal how much they knew.
Ms Rudd previously told the committee she believed Dame Lowell, who denies allegations she used racist language, had quit because she was "a long way from home" and was "too lonely".
Mr Sedwill was sitting next to the Home Secretary at the September 7 hearing as she added: "That's all the information I have about why she decided to go."
But last night, the Home Office said it was made aware of worries about Dame Lowell's conduct on July 29, when Ms Rudd had taken over from Mrs May, who became Prime Minister on July 13.
Dame Lowell resigned on August 4.
Officials were unable to say whether similar worries had been raised before that date and the PM's official spokeswoman has declined to comment on whether Mrs May was informed during her time as home secretary.
Labour has called on Mrs May and Ms Rudd provide assurances that there was no cover up.
Shadow home secretary Diane Abbott said: "These are grave allegations and the Home Secretary and Prime Minister must address them urgently.
"Despite being given every reason not to trust the establishment, the victims of child sex abuse had put their faith in this inquiry. We cannot afford to lose their trust again.
"We must be given an assurance that there was no attempt to cover the accusations made about Judge Goddard. Because if true, it would mean that the Home Secretary knowingly put at risk the integrity of the entire inquiry."
Dame Lowell's replacement, Professor Alexis Jay, will on Monday provide an update on the progress of an internal review of the inquiry's approach to its investigations, it is understood.
Prof Jay is also due to appear before the Commons Home Affairs Committee on Tuesday.