U.S. Ambassador to Russia Jon Huntsman has met with a Michigan man accused of spying. Russian police detained Paul Whelan nearly a week ago, and on Thursday Russia's state-run media said he had been formally indicted on espionage charges.

Whelan's family has said he's innocent and they're worried about his safety. Huntsman visited Whelan at the Lefortovo Detention Facility on Wednesday and also had a phone call with his family, according to the State Department, which is offering limited information at this time.

Russian media is reporting that Whelan was picked up in his hotel room and accused of trying to recruit Russians to get information for the U.S.

Whelan's brother David told CBS News his brother was in Moscow for the wedding of a friend and had been to Russia several times. David said the family last heard from Paul, a retired U.S. Marine, on Friday, "which was very much out of character for him, even when he was traveling."

According to the military website Stars and Stripes, Whelan gave wedding guests a tour of the Kremlin and some museums on Friday morning. He never made it to the wedding that night.

Since 2017 Whelan has worked for an auto parts company called BorgWarner, most recently as director of global security. He spent 14 years in the U.S. Marine Corps and, according to the military, was discharged in 2008 for bad conduct related to larceny.

On Wednesday Secretary of State Mike Pompeo said the U.S. would demand Whelan's immediate return if the detention was not deemed appropriate.

The charges he faces carry a prison sentence of up to 20 years.

What Whelan is accused of

While the Russian government has given very little information publicly on the American's detention, the country's media outlets cited investigators as saying Whelan was caught "red-handed" after receiving "state secrets" from an unidentified Russian national.

According to the Rosbalt news outlet, which is thought to have exclusive sources via indirect links with the Kremlin, Whelan is accused of trying to recruit a long-time Russian acquaintance to gain a list of names of employees of a Russian security agency.

Rosbalt cited an anonymous source in Russia's intelligence community as saying that Whelan had a profile on a Russian version of Facebook called VKontakte, where he would establish and foster contact with Russian nationals "targeted" for their presumed access to classified information.

The news site quoted a Russian lawyer representing Whelan as saying he could not discuss the case due to a non-disclosure agreement, but that his client was hoping for an objective investigation, and the possibility of release on bail pending trial.

"I was surprised to see him being so confident," Vladimir Zherebenkov, a high-profile criminal defense lawyer in Moscow, told The Associated Press.