Britain's Prince Andrew has accepted an apology from the police after armed officers stopped him in the gardens of Buckingham Palace.
The incident came days after two men were held in a security breach at Queen Elizabeth's London residence.
Police shouted at the 53-year-old prince, fifth in line to the throne, to "put your hands up and get on the ground", the Sunday Express newspaper reported, citing an unnamed royal source.
The officers had apparently failed to recognise the prince.
He was strolling the grounds in broad daylight in the late afternoon after attending an event in London on Wednesday.
In a statement, Prince Andrew said: "The police have a difficult job to do balancing security for the royal family and deterring intruders, and sometimes they get it wrong.
"I am grateful for their apology and look forward to a safe walk in the garden in the future."
London's Metropolitan Police earlier confirmed that two of its officers had stopped a man in the palace gardens and asked him to verify his identity.
"The man was satisfactorily identified. No weapons were drawn and no force was used," the police said in a statement that did not name the prince.
Two days earlier, police arrested a man who had been found inside the palace on suspicion of burglary, trespass and criminal damage.
A second man was arrested outside the palace on suspicion of conspiracy to commit burglary. Both men were released on bail.
The queen was not in the palace at the time, but in her castle in Balmoral in Scotland.