The "Sapphire" ship had already arrived to the Romanian port of Sulina.
It was seized on Feb. 26 when it arrived at Snake Island, which had been attacked and occupied by Russians, to help the surviving Ukrainians or collect the killed ones.
On March 9, the ship's crew was forced to take the ship to the city of Sevastopol in Crimea. Later all 19 crew members were released from Russian captivity as part of the first prisoner exchange.
In total, the Russian army has seized three Ukrainian ships since the beginning of the full-scale invasion on Feb. 24.