MOSCOW (Reuters) - The United States rejected on Wednesday a suggestion it seek a prisoner swap involving a former U.S. Marine jailed in Russia for nearly a year over spying allegations, and called for his immediate release.

FILE PHOTO: Former U.S. Marine Paul Whelan, who was detained and accused of espionage, stands inside a defendants' cage during a court hearing on extending his pre-trial detention, in Moscow, Russia October 24, 2019. REUTERS/Tatyana Makeyeva

Paul Whelan, who holds U.S., British, Canadian and Irish passports, was detained by agents from Russia’s Federal Security Service in a Moscow hotel room on Dec. 28 last year.

After a U.S. diplomat visited him in jail on Wednesday, the U.S. embassy complained about Whelan’s declining health and called Russia’s treatment of him “shameful”, saying Moscow had refused to allow the diplomat to bring him Thanksgiving dinner.

Moscow says Whelan was caught red-handed with a computer flash drive containing classified information. Whelan says he was set up in a sting and had thought the drive, given to him by a Russian acquaintance, contained holiday photos.

He has been held in pre-trial detention while investigators look into his case.

Whelan’s Russian lawyer earlier this month urged the United States and other countries to push for a prisoner swap with Moscow that could get his client released.

But Julie Fisher, the chargée d’affaires at the U.S. Embassy in Moscow, dismissed any such exchange.

“There is no need to discuss a swap,” Fisher told reporters after visiting Whelan in prison. “There is no evidence, no crime,” said Fisher. “They need to release him. Paul has not been charged with a crime.”

Fisher also complained about what she said was Whelan’s declining health and about what she said was the Russian refusal to allow an outside doctor into prison to examine him.

He had not been allowed a single phone call to his family during the 11 months of his detention, and the U.S. Embassy said Fisher had not been allowed even to deliver Whelan a Thanksgiving dinner on Wednesday.

“Russian authorities denied Paul Whelan the minor comfort of a Thanksgiving dinner today. As American families around the world gather, Paul marks 11 months in prison and can’t even call his parents. This is shameful treatment,” tweeted Rebecca Ross, the U.S. Embassy’s spokeswoman.