A man with dual Russian and German citizenship was sentenced to 13 years in prison for allegedly spying for the German intelligence service in a closed-door trial in Moscow in March, according to German media.

Der Spiegel magazine reported that a court in the Russian capital convicted him in the trial in which he was accused of passing Russian state secrets to the BND, Germany’s intelligence agency.

His fiancee assured Spiegel that the man never worked for German espionage. According to the German weekly, the BND informed the federal government that the convicted man was never an agent of the BND.

Family members and friends asked officials in Berlin for help. A spokesman for the Ministry of Foreign Affairs told the German Agency yesterday that German diplomacy is aware of the case, but refrained from going into details.

“It concerns a person with German and Russian citizenship. The German Embassy in Moscow and the Ministry of Foreign Affairs have been following the case closely from the beginning and have been and remain in contact with the Russian authorities through various channels to secure consular access.”

The embassy is also in contact with the man’s relatives, he added.

Russian newspaper Kommersant reported in March that the man was sentenced to 13 years and three months in prison. During her reporting, she confessed to working with the BND and refused to cooperate with the authorities in exchange for a reduced sentence to “uncover” another case.

According to Kommersant, the other case was the espionage prosecution of journalist Ivan Safronov, who was sentenced to 22 years in prison for treason last year.