Russian authorities acknowledged that the Moskva sank, but said only that the vessel went down following a fire on board and the explosion of ammunition.
Dmitry Shkrebets, the father of a conscript aboard the ship, wrote a post on the Russian social network Vkontakte claiming his son, Yegor Shkrebets, had been on the ship and served as a ship's cook.
"On the night of April 13 to April 14, a tragedy occurred, the truth about which we have yet to find out, the official report of the Ministry of Defense states that a fire broke out on the ship and the ammunition detonated," the elder Shkrebets wrote.
"It was reported that the entire crew had been evacuated. It's a lie! A blatant and cynical lie!"
He said he was informed that his son was not listed among the dead and wounded and was on a list of missing sailors.
"After my attempts to clarify the data on the incident, the cruiser commander and his deputy stopped communicating," Shkrebets said. "I asked directly why you, the officers, are alive, and my son, a conscript soldier, died?"