The family of Paul Whelan, a retired U.S. Marine recently detained on espionage charges in Russia is insisting on his innocence, saying he was abroad only for a wedding when he was taken into custody on Friday.

David Whelan, who identified himself as Paul Whelan’s brother, posted a statement on Twitter on Tuesday that said his brother abruptly fell off his family’s radar on Dec. 28, which was “very much out of character for him.”

“We are deeply concerned for his safety and well-being. His innocence is undoubted and we trust that his rights will be respected,” the statement read.

My brother was detained by the Russian government on Friday as an alleged spy. While the law library + info focus will remain, you may see an increase in off-message topics until we get him safely home. pic.twitter.com/2HIF1UmS1b — David Whelan (@davidpwhelan) January 1, 2019

There were no further updates on his condition as of Tuesday evening, Paul Whelan told HuffPost in an email.

The Russian Federal Security Service, Russia’s security agency, confirmed Whelan’s arrest in a statement that accused him of conducting a “spy mission” while in Moscow, according to a translation by NPR.

An espionage conviction in Russia can carry a prison sentence of 10 to 20 years, Reuters reported.

Reuters Paul Whelan in a photo provided by his family on Jan. 1. A U.S. citizen, he was detained in Russia on Dec. 28, 2018, for suspected spying.

A spokesperson for the U.S. State Department confirmed for HuffPost that an unspecified U.S. citizen was detained by Russian authorities.

“We have been formally notified of the detention by the Ministry of Foreign Affairs,” a State Department spokesperson said in an email. “Russia’s obligations under the Vienna Convention require them to provide consular access. We have requested this access and expect Russian authorities to provide it.”

Whelan’s arrest follows Russian gun rights activist Maria Butina’s pleading guilty to conspiracy against the U.S. in December. The close timing of his detention has led to speculation that it was done in retaliation.

He works as the director of global security and investigations for automotive components manufacturer BorgWarner, which is based in Auburn Hills, Michigan, the company said in a statement.

Before that, he worked in global security operations for the staffing firm Kelly Services and was a police officer and deputy in Michigan, the Daily Beast reported.

A website listed as belonging to Whelan describes him as enthusiastic about Russian history and culture and said he has studied the language during his travels to the country.

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