ZURICH (Reuters) - Switzerland returned around 3.5 million euros ($3.91 million) held by a close relative of former Tunisian president Ben Ali to Tunisian authorities as part of the country’s stolen assets recovery process, Swiss authorities said on Friday.

The Swiss government froze assets held in Switzerland by the deposed Tunisian president and his entourage in early 2011, the foreign ministry said, part of an effort to prevent the flight of capital suspected of having been illicitly acquired.

Criminal investigations have since been opened in both countries.

“Acting on a request for mutual legal assistance from Tunisia, on 26 May 2017 the Office of the Attorney General of Switzerland ordered the transfer of an additional amount of approximately 3.5 million euros,” Switzerland’s foreign ministry said in a statement.

“The assets had been frozen in Switzerland in connection with a close relative of the former president of Tunisia, and are being transferred to the current Tunisian authorities with that person’s agreement.”

The transfer follows a smaller restitution of 250,000 Swiss francs ($256,383.96) made to Tunisia in May 2016.