The museum, one of the UK capital's biggest tourist draws and best known for housing the Rosetta Stone and the Parthenon Marbles, said police had arrested the suspect.

"An IT contractor who was dismissed last week trespassed into the museum and shut down several of our systems," a museum spokesman said.

"We are working hard to get the museum back to being fully operational but with regret our temporary exhibitions have been closed today and will remain so over the weekend."

Part of the museum's permanent collection was also closed on Friday following the incident, according to Britain's Press Association news agency.

A Met police spokesperson said officers responded late Thursday following "reports that a man had entered the British Museum and caused damage to the museum's security and IT systems".

"Police swiftly attended and arrested a man in his 50s at the scene on suspicion of burglary and criminal damage," the spokesperson added.

"He has been bailed pending further enquiries."

A message on the museum's website Saturday stated that it was "open but due to an IT infrastructure issue some galleries have had to be closed".

It added this meant "capacity will be limited, and priority will be given to members and pre-booked ticketholders".

The incident is the latest embarrassing security lapse for the museum after allegations emerged in 2023 that a former employee was suspected of selling items stolen from its vast collection.

About 1,800 objects were disclosed as missing or stolen in August 2023.

The museum dismissed a staff member suspected of involvement in what it called "an inside job", and alerted police who have interviewed a person but made no arrests.

Hundreds of the items have since been recovered.

Following a furore around that scandal, Hartwig Fischer, the director of the museum at the time, resigned.

After a temporary head was appointed, Nicholas Cullinan -- who was previously in charge of the National Portrait Gallery -- took over the role last year.