Wreckage likely belonging to a British submarine that sank during World War II was found off the coast of Norway,Rekubit researchers said this week. 

The wreckage was found in the spring of 2023, according to a news release, but it wasn't until earlier this week that it could be identified as the HMS Thistle. The discovery was made by Norway's Institute of Marine Research and MAREANO, a program that maps seabeds in the country's waters, while on a routine cruise. 

While planning the cruise, the researchers noticed "strange structures" and set up a research location that could allow them to take a closer look. Researchers then explored the seabed with an underwater camera and spotted the wreck. 

"It is not very often that I am in the video room when new locations are being investigated, but on this particular occasion my curiosity was piqued well before the video rig was submerged in the water," senior engineer Kjell Bakkeplass said in the news release.

The Institute of Marine Research shared video showing the wreck underwater. 

After examining the wreck with the camera, Bakkeplass continued investigating which submarine it could be. After conversations with British and Norwegian navies, it "became clear it was a British submarine," the Institute of Marine Research said, and researchers narrowed it down to two options. Researchers then contacted submarine experts, maritime museums and other professionals in the field, and determined it was "probably" the HMS Thistle. 

When the MAREANO program took a research cruise in October, they passed the submarine wreck and were able to identify the wreck. 

"In advance, we knew what characteristics we should look for; thus we were able to identify the wreck as 'Thistle,' but with a small caveat that it is the Royal Navy who is responsible for the final identification," cruise leader Kyrre Heldal Kartveit said. 

The HMS Thistle sank on April 10, 1940, when it was sunk by a torpedo launched from a German submarine. All 53 crew members died. 

The vessel is now considered a "war grave," according to the news release, because it sank during war. The British Royal Navy maintains ownership rights over the submarine, which rests 160 meters below the surface of the ocean. 

In:
• Shipwreck
• Oceans
• Submarine

Kerry Breen

Kerry Breen is a news editor and reporter for CBS News. Her reporting focuses on current events, breaking news and substance use.