The Home Office's top civil servant will be questioned by MPs about the national inquiry into child sexual abuse today.
Mark Sedwill will appear before the Commons Home Affairs committee after it was disclosed that the former chairwoman of the probe, Dame Lowell Goddard, resigned days after the department was made aware of concerns about her "professionalism and competence".
Dame Lowell, a New Zealand high court judge, has strongly denied allegations against her - including claims that she used racist language - describing them as "falsities", "malicious" and part of a "vicious campaign".
On Monday Home Secretary Amber Rudd said concerns were raised with Mr Sedwill, the Home Office's permanent secretary, on July 29.
Less than a week later, on August 4, Dame Lowell resigned.
Answering an urgent question on the matter in the House of Commons, Ms Rudd insisted Home Office staff had behaved in an "entirely appropriate" way.
The inquiry's fourth chairwoman, Professor Alexis Jay, is also due to appear at the committee later.
On Monday she set out her strategy for the probe. Dismissing calls for it to "forget the past", she set out her aim to complete a "significant amount" of its work by the end of 2020.
Described as the most ambitious public inquiry ever in England and Wales, it was earmarked to take five years, but there have been suggestions it could run for as long as a decade at a cost of up to £100 million.
It has been dogged by controversy since it was set up by then-home secretary Theresa May in 2014.