Britain's troubled inquiry into child sex abuse has been thrown into doubt as New Zealand high court judge Dame Lowell Goddard became its third chairman to resign.
Dame Lowell said the investigation has struggled to shake off its "legacy of failure" with her shock resignation leaving abuse victims fearing there may be delays to the long-awaited inquiry.
Dame Lowell, 67, who was appointed in April 2015, had spent more than 70 days working abroad or on holiday during her time in charge.
An inquiry spokesman said she had spent 44 days in New Zealand and Australia on inquiry business and was entitled to 30 days' annual leave.
Campaign groups and politicians have called for a replacement to be found "urgently".
Dame Lowell did not give full reasons for leaving but said that accepting the job had been "an incredibly difficult step to take, as it meant relinquishing my career in New Zealand and leaving behind my beloved family".
The inquiry has been beset by setbacks since it was set up in 2014 amid claims of an establishment cover-up following allegations that a paedophile ring operated in Westminster in the 1980s.
Dame Lowell said: "The conduct of any public inquiry is not an easy task, let alone one of the magnitude of this.
"Compounding the many difficulties was its legacy of failure which has been very hard to shake off and, with hindsight, it would have been better to have started completely afresh.
"While it has been a struggle in many respects, I am confident there have been achievements and some very real gains for victims and survivors of institutional child sexual abuse in getting their voices heard.
"I have nothing but the greatest of respect for the victims and survivors, and have particularly enjoyed working with the Victims and Survivors Consultative Panel which I established."
Dame Lowell stated her resignation was "with immediate effect" as she quit in a letter to Home Secretary Amber Rudd on Thursday afternoon.
Ms Rudd said the inquiry would "continue without delay" and a new chairman would be found.
She described the inquiry, which has launched 13 investigations including strongly-denied claims linked to Lord Greville Janner, as the "most ambitious public inquiry ever established in England and Wales".
In accepting Dame Lowell's resignation, she wrote: "I know how personally committed you have been to ensuring that the inquiry is a success for those at its heart: the survivors and the victims.
"You have consistently demonstrated your desire to leave no stone unturned in order that the voices of those victims might be heard.
"It is a testament to your commitment that you have taken the difficult decision to stand down now, having set the inquiry firmly on course, and allow someone else to lead it through to the end. With regret, I agree that this the right decision."
Baroness Butler-Sloss stood down 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 former home secretary Leon Brittan, who died in 2015.