A museum in Denmark says it has solved the seven-decade mystery of a missing Nazi submarine. The Sea War Museum Jutland, in northern Denmark, says researchers found the German U-boat U-3523 on the seafloor just north of the country earlier this month.

The submarine was sunk on May 6, 1945, the day after Nazi forces surrendered in Denmark, parts of Germany and the Netherlands in World War II, according to the museum. For years there has been speculation that the sub, which was one of Nazi Germany's most advanced U-boats at the time, made it to South America carrying fleeing Nazi officers -- possibly even Adolf Hitler himself, according to some conspiracy theorists.

"After the war, there were many rumors about top Nazis who fled in U-boats and brought Nazi gold to safety, and the U-3523 fed the rumors," the museum said in a statement published on its website. "The Type XXI was the first genuine submarine that could sail submerged for a prolonged time, and the U-3523 had a range that would have allowed it to sail non-stop all the way to South America."

The museum has not raised the wreckage from the seafloor, and it's final resting position -- only nine miles from where the British navy reported sinking the sub as it tried to make a suspected escape. The fact that the wreck wasn't found 70 years ago left room for the speculation about a successful clandestine voyage to Argentina.

A graphic representation from the Sea War Museum Jutland in Denmark shows the wreckage of a Nazi German U-boat, which the museum says it found embedded in the seafloor north of Denmark. Sea War Museum Jutland

Images from the museum's scanning equipment, which located the wreck, show the German sub partially embedded in the seafloor, nose-first at about a 45 degree angle.

Get Breaking News Delivered to Your Inbox

It is about 130 yards under the surface, which will make recovery work difficult, and the museum said its research team still has no idea what might be aboard.

Denmark's Sea War Museum Jutland has registered the discovery of more than 400 vessels, many from the World War II era.