MOSCOW, January 4. /TASS/. London has requested consular access to US citizen Paul Whelan detained in Russia on suspicion of espionage who is also a British national, Russian Foreign Ministry Spokeswoman Maria Zakharova told TASS on Friday.

"He has the British citizenship. The British side has sent a request for a consular visit. Work on it is in progress," the diplomat said.

On Monday, the Russian Federal Security Service (FSB) said US citizen Paul Whelan was detained on December 28, 2018, in Moscow while on a spy mission. A criminal investigation was opened against him on espionage charges. He could face between 10 and 20 years in jail. US Ambassador to Russia Jon Huntsman visited Whelan at the Lefortovo pre-trial detention center on Wednesday.