China's Navy tried to hide that it's newest nuclear-powered submarine sank earlier this year, according to a CNN report citing two anonymous U.S. defense officials.

"The attack submarine was the first of its new Zhou-class line of vessels," the report said, citing one of the officials. "The Zhou-class submarines have a distinctive X-shaped stern, designed to improve maneuverability underwater."

The report said that the sub was docked in March at a shipyard close to the Chinese city of Wuhan. 

CNN reviewed Maxar imagery from June that showed the sub did not make it back to the pier.