Scotland Yard’s principal Twitter account, which is followed by more than 1.2 million people and is used to provide important alerts in times of crisis, tweeted a series of bizarre messages on Friday night after becoming “subject to unauthorised access”.

Many of the dozen errant tweets, some of which referred to the British rapper Digga D, were also repeated in press releases emailed out to journalists from the force’s official email address. Officers said they were “assessing to establish what criminal offences have been committed” over the security breach.

Met police Supt, Roy Smith, tweeted about the breach.

We are aware that the @metpoliceuk has been subject to unauthorised access and 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. RT — Supt Roy Smith (@roysmithpolice) July 19, 2019

Some of the tweets, since deleted, included:

‘Unauthorised access’ to Met Police Twitter account Photograph: Twitter

‘Unauthorised access’ to Met Police Twitter account Photograph: Twitter

‘Unauthorised access’ to Met Police Twitter account Photograph: Twitter

‘Unauthorised access’ to Met Police Twitter account Photograph: Twitter/PA

The messages were posted during a 40-minute period beginning at 11.16pm on Friday and the force’s media team was engaged in a game of cat-and-mouse as it struggled to delete the tweets as soon as they were posted.

In the early hours of Saturday, after apparently regaining control of its output, Scotland Yard said it believed the “security issue” related solely to the external service the Met’s press bureau uses to issue news releases. It said the MyNewsDesk service automatically spreads content to the Met’s website and Twitter account once it is published, as well as sending corresponding emails to subscribers.

“While we are still working to establish exactly what happened, we have begun making changes to our access arrangements to MyNewsDesk. We apologise to our subscribers and followers for the messages they have received.

“At this stage, we are confident the only security issue relates to access to our MyNewsDesk account,” it added.

“There has been no ‘hack’ of the Met police’s own IT infrastructure.”