ATHENS, Greece (AP) — The mother of a Russian man jailed in Greece pending three extradition requests for alleged bitcoin fraud has appealed for his release, ahead of another legal bid to end his detention.

Vera Vinnik said Tuesday that Greek authorities have shown "no mercy" to Alexander Vinnik, who has been imprisoned for 27 months even though his lawyers say he hasn't been charged with anything in Greece.

Greece's supreme court will assess Wednesday whether to annul its previous, separate decisions to extradite the 40-year-old Vinnik to the U.S. and to France.

Vinnik was arrested during a Greek family holiday in 2017 on a request from the U.S., which accuses him of laundering billions of dollars using bitcoin, the virtual currency.

Should Vinnik win Wednesday's appeal, he'll be freed or extradited to Russia.