When I woke up this morning was listening to NPR news break on clock radio. They had mentioned that Paul Whelan was detained and was a dual citizen of the US and the UK. Don't know if that has been covered. Spying for the UK?
https://www.standard.co.uk/news/world/paul-whelan-arrest-british-former-marine-detained-in-russia-after-being-accused-of-spying-a4030186.html
A British citizen has been detained in Russia after he was accused of spying.
Former US marine Paul Whelan, who is a dual citizen, has been accused of receiving a computer memory stick containing a secret list of Russian agents.
His brother David said on Tuesday that he had no idea why his brother was targeted by the Russian security services.
He said Paul was in Moscow to help plan the wedding of another former Marine because he had been to Russia several times before.