The Metropolitan Police official Twitter page appears to have been hacked.
Late on Friday, a series of tweets were sent out calling for the release of drill rap artist Digga D.
The posts also linked to false press releases regarding the rapper.
Scotland Yard's press bureau email account also appears to have been accessed.
Emails linking to bogus releases were also sent expressing anti-police sentiments and calling for Digga D's release.
A Scotland Yard superintendent said the Met's official account has "been subject to unauthorised access".
Superintendent Roy Smith tweeted: "Our media team are working hard to delete the messages and ensure the security of the account. Please ignore any Tweets until we verify that it is back under official control."