Jailed Russian opposition leader Aleksei Navalny said on April 16 that prison authorities have threatened to put him in a straitjacket to force-feed him unless he halts his hunger strike.

Navalny, 44, announced a hunger strike at the end of last month in protest at what he said was the refusal of prison authorities to allow him to receive proper medical care for acute back and leg pain.

In an Instagram post, Navalny said an official told him that blood tests showed his health was deteriorating and threatened to force-feed him if he continues his hunger strike.

“And then she detailed the joys of force-feeding to me. Straitjacket and other pleasures,” the politician said, adding that he urged the officials not to do it, “pointing to a clause in the law.”

Navalny did not elaborate on what he meant by “other pleasures.”

Navalny was arrested in January on his arrival from Germany where he was treated for poisoning in Siberia with what was defined by European labs as a nerve agent in August last year. He has accused President Vladimir Putin of ordering the poisoning, which the Kremlin has denied.

A Moscow court sentenced the opposition leader in February to 2 1/2 years in prison on charges he says were politically motivated.

Based on reporting by Reuters and AP