The German prosecutor general has charged both men with “high treason in a particularly serious case”. However, there is no public information about the timeline of Carsten L.’s recruitment by the FSB and his espionage for the Russians. He reportedly met his accomplice, Arthur E., a Russian-born German diamond trader, in Bavaria in 2021. After being recruited by Carsten L., Arthur E. is believed to have traveled frequently between Germany and Russia. During those trips, he is thought to have met with FSB officers in order to provide them with intelligence and receive payments.

When they announced the arrests of the two men back in January of this year, German officials said they had been tipped by a foreign intelligence agency. The foreign intelligence agency had allegedly found a document from the BND’s internal files in the possession of an unnamed Russian spy agency. However, the identity of the intelligence agency that provided the tip to the Germans is among several important details about this case that remain unknown for the time being. Among them are the estimated duration of Carsten L.’s alleged espionage for Moscow, the damage he caused to German intelligence, as well as his motives for spying for the FSB.