US diplomats working in the Russian capital have informed UK officials of Whelan's arrest and the fact that he is also a UK national, The Times newspaper reported.
"Staff have requested consular access to a British man detained in Russia after receiving a request for assistance," the UK Foreign Office told the outlet.
Whelan is the director of global security for Michigan-based automotive components supplier BorgWarner. Media have reported, citing his brother, that Whelan went to Russia to attend a friend’s wedding but never made it to the event.
Moreover, media have reported that Whelan was a former US marine. His service record, released by the media, showed he had been convicted in 2008 on theft charges.