The coroner due to hear inquests into the deaths of Diana, Princess of Wales and Dodi Al Fayed has announced he is withdrawing from the cases.
Princess Diana died in Paris on 31 August 1997.
Michael Burgess, coroner of the Queen's Household, asked for the inquests to be handled by a "senior judicial figure".
Mr Burgess blamed a "heavy and constant" workload for his decision.
He said he wanted to pass on the responsibility in advance of an official report into the 1997 Paris crash being released.
Buckingham Palace said that the Queen had been informed of the development.
It is not yet known whether Mr Burgess' decision will delay the inquests.
A spokeswoman for Mr Burgess, who is also the coroner for Surrey, said the cases would "demand a good deal of time and a clear focus, free of distractions".
"They are too time-consuming for a coroner who has only limited resources and who, even without these cases, has a very full workload and busy district with which to deal," she added.
The Lord Chancellor had agreed to Mr Burgess' request that he "nominate a suitable senior judicial figure to be appointed as deputy to hear these two cases," the spokeswoman said.
"It will mean that a senior and experienced judicial figure will deal with these matters in a focussed and dedicated way until they are concluded and Mr Burgess can attend to his full-time appointment."
BBC Royal correspondent Peter Hunt said the unexpected announcement has come at an important stage of the probe into the crash.
"This is a surprise development in an investigation into the death of a princess, about which conspiracies abound," he said.
"Michael Burgess has thrown in the towel at a critical juncture. Mr Burgess was about to be handed the findings of a police investigation, led by Lord Stevens, into the Paris crash.
"The onus would then have been on him to announce how he was going to conduct the Diana and Dodi Fayed inquests. His successor, possibly a judge or a retired one, will now shoulder that burden."
Our correspondent said the handover of the police report will be delayed while Mr Burgess' replacement gets to grips with the complexities of the case.
Diana and Mr Al Fayed died after the Mercedes in which they were travelling crashed in the Alma underpass in Paris on 31 August 1997.
They were being pursued by photographers after leaving the Ritz Hotel.
The official report into the crash is being prepared by former Metropolitan Police Commissioner Lord Stevens.
He has said that the inquiry into the death of Diana was "far more complex than any of us thought" and in May this year said fresh forensic evidence and witnesses had been found.