A man has been arrested after appearing to try and rush toward the coffin and catafalque of Queen Elizabeth II.
Footage of the incident, which occurred on Friday evening, shows a man being tackled to the floor of Westminster Hall after reportedly approaching the coffin of the late monarch.
In front of stunned onlookers, the man is apprehended by several security guards and police officers.
A statement from the Metropolitan Police, per ITV News, states: "Around 22:00hrs on Friday 16 September officers from the Met's Parliamentary and Diplomatic Protection Command detained a man in Westminster Hall following a disturbance.
"He was arrested for an offense under the Public Order Act and is currently in custody."
The moment was captured by cameras currently live-streaming the late Queen lying in state. Following the incident, the feed was cut.
Footage appearing to show the incident was shared to Twitter:Per BBC News, a Parliament spokesperson has said: "We're aware of an incident in Westminster Hall, in which a member of the public moved out of the queue and towards the catafalque.
"They have now been removed from the hall and the queue restarted with minimal disruption."
No further details have been revealed.
One witness who was in Westminster Hall at the time told the Daily Mail: "We saw [the man] in the queue from the beginning of the queue and throughout the day, he was by himself.
"When we entered the room we were at the top of the stairs when we saw the incident. A lady screamed as it happened it was quite unnerving. Although he was detained and people kept calm and carried on."
Another witness, who was queuing with her young niece, added: "A person decided they were going to push my seven-year-old niece out the way, run up to the coffin, lift up the standard and try to do I don't know what. She was grabbed out the way and the police had him within two seconds.
The woman described the moment as "terrible, absolutely terrible, so disrespectful and unbelievable".
Queen Elizabeth II is currently lying in state until her funeral on Monday, September 19.
Lying in state is when a closed coffin is placed on view, allowing members of the public to come and pay their respects.
The late monarch's coffin has been placed on a raised platform - called a catafalque - and has been draped with the Royal Standard flag.
The tradition dates back to the 17th century, when Stuart sovereigns would lie in state for a number of days prior to their funerals.
In the UK, the tradition is often reserved for members of the Royal Family, but former Prime Minister Winston Churchill is one of the few non-royals to lie in state at Westminster Hall back in 1965.
As of this writing, BBC News reports that the queue to see the late Queen lying in state has currently reached "at least 24 hours".