The family of an American man detained by Russia on spying charges said on Tuesday that he is innocent and that he was visiting Moscow for a wedding.
Paul Whelan - a retired U.S. Marine - was arrested last week during what Russia called "an act of espionage,” and said on Monday that a criminal case had been opened against him.
Under Russian law, Whelan could face a prison sentence between 10 and 20 years.
In a statement released on Twitter, the Whelan family said "his innocence is undoubted." His brother David said he was staying with the wedding party for a fellow former Marine in Moscow.
The brother declined to comment on Whelan’s work status at the time of his arrest and whether his brother lived in Novi, Michigan, as address records indicate.
The U.S. has leveled its own accusations of spying against a Russian national.
That case resulted in a guilty plea from Maria Butina in a deal with prosecutors.
In December, she admitted to working with a top Russian official to infiltrate American conservative activist groups as an agent for Moscow.