Britain's foreign ministry mistakenly sent a picture of the wrong Dmitri to accompany a sanctions announcement on Thursday, mixing up sanctioned businessman Dmitri Lebedev with former Russian president Dmitry Medvedev.
British Prime Minister Boris Johnson has pledged to speed up sanctions while stressing the need to move carefully, saying "we have to get it right" to avoid a "brick wall of lawyers".
But the foreign ministry got it wrong in a tweet announcing sanctions on Bank Rossiya chairman Lebedev, instead tweeting out a picture of Medvedev, who is now deputy chairman of Russia's Security Council.
Medvedev, a close ally of President Vladimir Putin, is not on the official UK Sanctions List.
The tweet has now been deleted after several Twitter users pointed out the error.
"This was an administrative error which was quickly spotted and rectified," said a spokesperson for the Foreign, Commonwealth and Development Office which tweeted the image.
(Reporting by Alistair Smout; Editing by Gareth Jones)