According to documents posted on social media by Matios, the court in Ukraine's southern city of Odesa issued the ruling on July 29 regarding the seizure of the tanker Nika Spirit.

"The court seized the said vessel," Matios said. "We did it legally."

The Russian vessel was seized on July 25 by Ukraine's SBU security service and the Military Prosecutor's Office for its alleged involvement in an incident in November 2018 off the coast of Ukraine's Russia-occupied Crimean Peninsula.

The SBU says the Russian tanker is material evidence in a case over the November 2018 Kerch Strait incident, alleging that the tanker was used to block three Ukrainian naval ships as they attempted to transit the Kerch Strait from the Black Sea to reach the Sea of Azov.

The Russian Navy fired at the Ukrainian ships in the altercation and seized the vessels along with 24 Ukrainian sailors on board.

Russia continues to hold the Ukrainian sailors in detention and plans to put them on trial, despite a May 25 ruling by the United Nations' Hamburg-based International Tribunal for the Law of the Sea that Russia must "immediately" release the sailors and Ukrainian ships.

Russia has said the international maritime tribunal has no jurisdiction. It claims the Ukrainian ships illegally entered Russian territorial waters when they were off the coast of Russia-annexed Crimea.

The UN tribunal's decisions are legally binding, but it has no power to enforce them.

The Russian Embassy in Ukraine told TASS on July 30 that Russia's consulate-general in Odesa has lodged a note with Ukraine's Foreign Ministry demanding explanations for the seizure of the Russian tanker.

Ukrainian investigators seized documents on board and questioned its 10 crew members. The 10 Russian crew members were later released and were allowed to return to Russia.

The embassy said Russia has "not received any official documents" from Ukraine concerning the seized tanker and has not yet replied to the diplomatic note.

With reporting by Reuters, AFP, Interfax, and TASS