The captain of the Royal Navy's HMS Queen Elizabeth aircraft carrier has been removed from the ship amid claims he misused an MoD car.
Commodore Nick Cooke-Priest was flown off the ship as it was anchored in the Firth of Forth.
The navy said it was a "precautionary measure" in an "ongoing investigation".
It earlier said Cdre Cooke-Priest was being "reassigned" duties, but would sail from Rosyth on the Firth of Forth to Portsmouth as planned.
Despite being removed from the ship, it is understood he remains officially in charge and will formally hand over to a new commanding officer of the £3bn carrier later this month.
Cdre Cooke-Priest, who joined the Royal Navy in 1990, has been in command of HMS Queen Elizabeth since October last year.
Last week it was revealed the navy was investigating reports he had used his Ministry of Defence car - a Ford Galaxy - for his own personal trips.
Anyone who has use of an MoD vehicle can only use it for official business, with each mile needing to be recorded.
But the BBC has been told that thousands of miles on the clock of Cdre Cooke-Priest's vehicle have not been accounted for.
A Royal Navy spokesman said: "In light of the ongoing investigation, as a precautionary measure, to protect the individual and the ship's company, the Royal Navy has decided that Capt Cooke-Priest will not be at sea with HMS Queen Elizabeth."
The Royal Navy has already been accused of handling this affair badly, and its latest actions may make matters worse.
Removing a commanding officer from his ship while still at sea is nothing short of brutal, particularly when many have already spoken out in his support.
But it's a sign that Cdre Cooke-Priest had already lost the trust of his superiors - and at least some of his crew.
Not a mutiny, but certainly a question of confidence.
The offence of using a work car for personal trips may appear to be relatively minor. But to the top brass it was more serious.
Navy sources have told the BBC he had repeatedly ignored warnings.
It wasn't just about breaking rules. It was seen as a sign of "arrogance and sense of entitlement".
Friends of Cdre Cooke-Priest still plead that he was ignorant of the rules. But it is hard to see how his career will recover.
What was at first described as "administrative" action might now turn into more serious disciplinary proceedings.