New Zealand judge Dame Lowell Goddard has abruptly resigned as head of the independent inquiry into child sexual abuse in the United Kingdom, saying she should have started with a clean slate.
Dame Lowell, 67, was appointed in February 2015 to lead the inquiry following the resignation of two previous chairwomen.
Her resignation letter, which was posted to the home secretary's website, contained just two lines.
"I regret to advise that I am offering you my resignation as Chair of the Independent Inquiry into Institutional Child Sexual Abuse, with immediate effect. I trust you will accept this decision," Dame Lowell wrote.
She also released a statement which said it was a difficult decision to take on the role and leave her family in New Zealand.
The inquiry had a "legacy of failure" which had been hard to shake off, she said.
"With hindsight it would have been better to have started completely afresh."
Her shock resignation has left abuse victims fearing there may be delays to the long-awaited inquiry.
Dame Lowell spent more than 70 days working abroad or on holiday during her time in charge. An inquiry spokesman says she spent 44 days in New Zealand and Australia on inquiry business and was entitled to 30 days' annual leave.
The job's basic salary of around £360,000 ($NZ670,450) plus a £110,000 rental allowance and other perks made her the UK's highest paid public servant.
The inquiry has been marred by setbacks since it was set up in 2014 amid claims of an establishment cover-up following allegations that a paedophile ring operated in London political circles in the 1980s.
Home Secretary Amber Rudd says the inquiry - "the most ambitious public inquiry ever established in England and Wales" - will continue without delay and a new chair will be found.
Baroness Butler-Sloss stood down from the inquiry in July 2014 amid questions over the role played by her late brother, Lord Havers, who was attorney-general in the 1980s.
Her replacement Dame Fiona Woolf resigned following a barrage of criticism over her "establishment links", most notably in relation to the late former home secretary Leon Brittan.
The inquiry's terms of reference say that its purpose includes considering "the extent to which state and non-state institutions have failed in their duty of care to protect children from sexual abuse and exploitation".
Lord Greville Janner, who died aged 87 in December, is alleged to have abused children over a period of 30 years in children's homes and hotels.
Some of Lord Janner's accusers have started civil proceedings to sue his estate, according to his son Daniel Janner QC.
"I was about to demand Justice Goddard's resignation tomorrow as she had refused my application last week to adjourn the inquiry pending the civil proceedings," Mr Janner said.
"The obscenity of a proxy prosecution against a dead and innocent man who cannot defend himself must stop.
"This is a manifestation of a national frenzy. My late father is not an institution and Goddard was set up to look at institutional failings."