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

MOSCOW (Reuters) - A senior U.S. diplomat on Monday called for Russia to free Paul Whelan, a former Marine accused by Moscow of espionage, saying there was no evidence against him and he had committed no crime.

Deputy Chief of Mission Bart Gorman made the pre-Christmas appeal to Russia outside a Moscow prison after he and diplomats from Britain, Canada and Ireland had visited Whelan.

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.

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.

Gorman urged Russia to allow an outside doctor to examine Whelan, who has a medical condition, and for the former Marine to be allowed to phone his parents, something he has so far been denied.

“In a case where there is no evidence and no crime it’s time to have him released,” Gorman said.