According to two Reuters reporters who said they personally witnessed the delivery, Russia has transferred two more gas turbines to Crimea, in defiance of sanctions imposed after Russia annexed the peninsula from Ukraine in 2014.

The reporters said the dimensions and shape of the equipment they saw under tarpaulins at the port of Feodosia match the profile of Siemens gas turbines and generators.

“Siemens said earlier this week that at least two of a total of four turbines it sold to Russian state firm Technopromexport had been delivered to Crimea against its wishes and without its knowledge,” Reuters notes. The location of the other two systems was unknown.

Siemens filed a lawsuit on Tuesday demanding that Moscow return all of the turbines to the city of Taman, on the other side of the Black Sea from Crimea, where they were supposed to have been installed. Technopromexport signed a written commitment not to move these systems to Crimea, or transfer power generated by the turbines into the annexed territory, in line with European Union sanctions.

The reason these power generation systems are such a sensitive issue is that Crimea used to get its electricity from Ukraine, but the Ukrainians are disinclined to continue providing power while Russia holds the territory. A group of Ukrainian nationalists made this point two years ago by destroying some of the Ukraine-Crimea power lines, unleashing highly embarrassing rolling blackouts upon Russia’s newest colonial possession.

Russia has been spending a great deal of money furnishing Crimea with electricity. Equipment as sophisticated as the Siemens turbines would be vastly cheaper than anything Russia has come up with so far.

Kremlin spokesman Dmitry Peskov claimed on Thursday that the turbines sent to Crimea were Russian-built, while Technopromexport chose not to comment on the situation.

A far less disciplined government official in Crimea essentially shrugged and admitted to the crime, telling Reuters, “Come on, we can’t talk about that. You understand: sanctions, Siemens. Of course, this whole story is going to come out, but let it come out without us.”

Siemens is a German company with a very long history of quietly doing business with Russia—all the way back to the time of the czars, according to the New York Times—so the lawsuit is seen as highly unusual, and possibly part of an increasingly serious diplomatic rift between Russia and Germany.

The German government demanded answers from Siemens about the fate of its gas turbines on Wednesday.

“I would point out that it’s the company’s job to check whether their business falls under a sanctions regime,” said Steffen Seibert, a spokesman for Chancellor Angela Merkel. He called the alleged delivery of turbines to Crimea “remarkable and completely unacceptable.”

On Thursday, Russian media reported that Roman Filippov, chief executive officer of the Power Machines company, was detained “on suspicion of attempted divulgence of state secrets.” Power Machines is the Russian side of the joint venture that brought the Siemens gas turbines to Taman. It is unclear whether his detention is linked to the dispute over the missing turbines.