The Malaysian Maritime Enforcement Agency said May 29 that it found a cannon shell — reportedly from World War II — on a Chinese-registered ocean vessel, causing the agency to detain the ship and investigate if the barge was involved in the looting of two WWII British shipwrecks in the South China Sea, according to ABC News.

The agency said that it apprehended the Fuzhou, China-registered ship May 28 for anchoring without a permit off the southern shore of Johor, Malaysia. Furthermore, the agency reportedly believes the rusty cannon shell was linked to the seizure of dozens of unexploded artilleries and other relics found in a private scrapyard in Johor.

Malaysian media outlets claimed that illegal ocean salvage operators targeted the HMS Repulse and the HMS Prince of Wales, a pair of battleships that were sunk by Japanese torpedoes in the South China Sea in 1941. ABC News said that the cannon shell could be made from pre-war steel, a valuable material that can be smelted down and used in the manufacturing of scientific and medical equipment.

The Malaysian Maritime Enforcement Agency said it's currently working with officials from the National Heritage Department to properly identify the cannon shell.