It sounds like something out of a Sherlock Holmes mystery: A thief stole the keys to the historic Tower of London, home to the queen's Crown Jewels.
British authorities announced on Monday that some of the locks at the Tower of London had been changed after two sets of keys were stolen from the grounds last week, according to Agence France Presse.
An intruder was able to gain access to the site in the early hours of Nov. 6 when he or she allegedly stole the keys.
British newspaper the Guardian reported that police have launched an investigation into the matter. The Tower chiefs said the crown jewels were never at risk of being stolen, but admitted that security measures "were not carried out to the expected standard."
The BBC noted that the Tower is guarded by the Yeoman Warders or Beefeaters.
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ABC News reported that the burglar was spotted by the Tower's guards, but they did not immediately stop the suspect, instead radioing for help from their designated posts. The burglar then reportedly made it all the way to the gate at the main entrance before being apprehended.
The intruder was taken off site, but afterwards it was discovered that the keys were missing, according to AFP.
The spokeswoman said, "We can however confirm that during this incident, keys for a restaurant and conference rooms were taken together with a key to an internal lock to the Tower drawbridges that is not accessible from the outside," according to the BBC.
"It would not have been possible to gain access to the Tower with any of these keys," she said. "All affected locks were immediately changed."
A spokesman for Scotland Yard said, An allegation of theft has been made to police, which is being investigated," according to AFP.
The Metropolitan Police said no arrests have been made as of yet, according to the BBC.