Moscow, Jan 22 (IANS) A US citizen accused of espionage in Russia has been found with "evidence that constitutes state secrets", his lawyer said on Tuesday.

Paul Whelan, the global security director for the Michigan-based automotive components supplier BorgWarner, was arrested in Moscow on December 28, 2018, on suspicion of carrying out an act of espionage, according to the Federal Security Service (FSB), Russia's domestic intelligence agency.

He was found with evidence constituting state secrets when he was detained, Whelan's lawyer Vladimir Zherebenkov told CNN.

His family says he was in the country only for a vacation.

Whelan, 48, arrived in Russia on December 22 to attend a retired fellow Marine's wedding, his brother David Whelan told CNN.

On the day of his arrest he had been with the wedding party at the Kremlin, serving as a guide for wedding guests who were visiting Russia for the first time, his brother said.

Later that day, he didn't arrive at the wedding, and the newlyweds filed a missing person report with the Russian authorities, according to David Whelan.

The FSB announced Whelan's arrest on December 31.

Since his arrest, Whelan has been held without bail in Moscow's Lefortovo prison.

Zherebenkov told CNN that he filed an appeal against the detention in early January, calling it unwarranted and excessive.

Whelan's hearing will be held in Moscow City Court. If found guilty, Whelan faces up to 20 years in prison, Russia's state-run news agency TASS reported.