“The department has now investigated and confirmed that it was not genuine and that the messages and video call were a hoax.”

The statement gave no details of what was discussed during the exchanges, other than to say that the caller asked Cameron for others’ contact details.

The foreign office said Cameron was making the hoax public “in case the video of the Foreign Secretary is manipulated and subsequently used, and to ensure that others are aware of this risk.”

“Whilst regretting his mistake, the Foreign Secretary thinks it important to call out this behaviour and increase efforts to counter the use of misinformation,” the foreign office said.

Britain, which holds a national election on July 4, did not say who it believed was responsible for the hoax.

Cameron is not the first British foreign minister to be caught out by a hoax. In 2018 then-Foreign Secretary Boris Johnson discussed international relations and rude poetry with a hoax caller who pretended to be the Armenian prime minister.

In 2022, Britain blamed Russia for hoax calls to two ministers and an attempted call to a third.

Videos of one of those calls, to then defence minister Ben Wallace, later appeared online, prompting Britain to say they had been doctored and ask YouTube to remove them.