Reed was convicted last year on charges of endangering the lives of two policemen in Moscow while drunk, a charge he denied. He said the ruling was clearly political, and Washington called his trial a “theatre of the absurd”.

“We have received a report from an attorney that Trevor has begun a hunger strike to protest his arbitrary detention and Russian authorities’ numerous and flagrant violations of his basic human rights and his rights under Russian law,” the family said in a statement late on Monday.

There was no immediate comment about the hunger strike from the prison holding him. The US embassy in Moscow did not immediately respond to a request for comment.

Reed’s family did not say how long he planned to keep the hunger strike up, but urged US authorities to support him, noting comments by Washington during a hunger strike by jailed Kremlin critic Alexei Navalny earlier this year.

“We recall the strong response from this Administration when a Russian dissident went on hunger strike several months ago and look forward to our son receiving the same attention,” the family said.