Security fears have been raised after a woman allegedly broke into the Houses of Parliament on the same day that King Charles and Queen Camilla visited.
The intruder reportedly slept in a committee room and was discovered the next day, on May 3.
Officers were alerted and she was detained under the Mental Health Act, said the Metropolitan Police. The woman is believed to have been in a distressed state when found, and was taken to hospital.
Hours before she allegedly sneaked in without a parliamentary pass, King Charles and Queen Camilla met with Commons Speaker Lindsay Hoyle in preparation for their Coronation.
A security review is reportedly being carried out after the break-in, which came at a time when the Palace of Westminster was supposed to be on full alert.
Archie and Lilibet's titles 'need to be earned' by Harry and Meghan, says sourceFormer Met detective chief inspector Mick Neville expressed his disbelief over the breach in security, describing it as "extraordinary".
He told The Sun: "How did an uninvited woman, with no permission to enter Parliament, slip through the net and spend a night sleeping in a committee room?
"Luckily, it would seem that she was harmless, but this individual could have been a terrorist. Even more worryingly, the King and Queen were visiting around the same time she got in."
The Met Police confirmed that it was called to concerns for a woman's welfare.
A force spokesman said: "At 14:42hrs on Wednesday, 3 May, officers responded to concerns for the welfare of a woman at the Palace of Westminster.
"She was detained under the Mental Health Act and taken to hospital."