(Bloomberg) -- A French national detained in Iran for more than eighteen months was sentenced to eight years in jail for espionage, according to his lawyer, who described his client’s trial as a “masquerade.”

Benjamin Briere’s lawyer said the accusations were “baseless” and pressed French authorities to step in to help in his release and return.

“It is intolerable that Benjamin Briere would remain the hostage of a regime which continues to arbitrarily detain a French citizen to turn him into a bargaining chip,” attorney Philippe Valent said in a Tuesday statement.

The conviction comes at an intense time in the nuclear talks in Vienna where France -- as one of the main participants in the beleaguered 2015 Iran nuclear deal -- is involved in negotiations to revive the landmark accord that gave Tehran sanctions relief in exchange for strict limits on its atomic activities.

The Frenchman was arrested in May 2020 for taking photos with a drone in a nature reserve in allegedly prohibited zones, Valent told Agence France-Presse. Briere received a further eight-month sentence over propaganda allegations.

A spokesperson for France’s foreign affairs ministry said on Monday it was monitoring the situation “with the utmost attention and concern” but didn’t immediately respond to a fresh request for comment.

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