The automotive magazine, “Top Gear Russia,” accidentally published a photo of a classified Russian submarine, according to news reports.

The Centre for Analysis of Strategies and Technologies, a Moscow-based think tank, was the first to report on the image of the classified deep-water sub known as the AC-12 Project. The news was subsequently picked up by such news outlets as Slon Media and Business Insider.

The magazine apparently organized a photo shoot on the shores of the White Sea for the Mercedes-Benz GL450, a full-size sports utility vehicle, and didn’t realize it had captured the stealthy submarine cruising on the surface of the water in the background.

The vessel, nicknamed, “Losharik” after a children’s movie, is part of the Russian navy’s Northern Fleet, according to the Russian think tank. The magazine image of Losharika may be the highest-quality open source photo of the boat to date.

Russia over the past decade has reorganized its military forces, including its Northern Fleet, in part to protect its interests in the Arctic. The fleet falls under a formation called Northern Fleet-United Strategic Command, which includes forces on the border with Norway and in the high Arctic, according to published reports.