Prince Philip has surrendered his driving licence as prosecutors consider whether to bring charges over a crash that injured two women.
Philip, 97, voluntarily gave up his credentials to Norfolk Police on Saturday.
Police said a file on the investigation into the crash last month had been passed to the Crown Prosecution Service.
A CPS statement said the file would be reviewed before a decision to charge or not was brought, and noted that prosecutors "will take this development into account".
One lawyer had previously suggested the duke could avoid any potential prosecution for driving without due care and attention by giving up his licence.
Philip apologised for his part in the accident on the Sandringham estate in Norfolk when his Land Rover Freelander collided with another car, leaving two women needing hospital treatment.
On Saturday, a statement from Buckingham Palace said "the Duke of Edinburgh has taken the decision to voluntarily surrender his driving licence".
Norfolk Police confirmed Philip had "voluntarily surrendered his licence to officers".
"We review each file carefully before a decision is made and will take this development into account," police said.
Philip's driving woes began on January 17 when his car flipped over after he pulled out into a busy A road and collided with a Kia, carrying a nine-month-old boy, his mother and another passenger.
He escaped injury, but passenger Emma Fairweather broke her wrist and called for the duke to be prosecuted if he was found to be at a fault.
On Saturday, she told the Sunday Mirror: "Undoubtedly the roads will be safer now. It [the decision] won't have been easy for him to make as it is a loss of independence. But he can work around it."