The European Union has imposed travel bans and asset freezes on 12 new individuals involved in the annexation of Crimea, including Valentina Matviyenko, a former Russian ambassador to Malta, and the current head of Russia’s upper house of Parliament.

Ms Matviyenko was already included in a list of officials from Russia and Ukraine who were subjected to such sanctions by the United States following last Sunday’s referendum in Crimea.

The EU’s new sanctions, announced on Friday after the meeting of the European Council, adds to an existing list of 21 officials affected by travel bans and asset freezes.

Ms Matviyenko’s travel ban is ironic because last December she was honoured by Malta on Republic Day by being awarded an honorary membership to the National Order of Merit in recognition of her contribution towards enhancing ties between Malta and Russia. She is now no longer allowed to visit Malta.

She served as ambassador to Malta between 1991 and 1995. As chairwoman of the Federation Council of the Russian Federation, Matviyenko is the third most senior official in Russia, after Russian President Vladimir Putin and Prime Minister Dmitry Medvedev.

The individuals targeted by the sanctions are seen as having played an important role in the referendum in Crimea, which the US and EU consider illegal.

Crimea’s Parliament declared the region an independent state following Sunday’s referendum, which was approved by 97 per cent of voters, and applied to Moscow to join Russia.

On Monday Mr Putin and the leaders of Crimea signed a Bill to absorb the region into Russia while on Friday he signed the treaty on Crimea joining the Russian Federation, after this was approved by the Russian Parliament.