It said Gasum tanker Coral Energice was in the Baltic Sea port of Vysotsk on April 24 and left empty. Another, Coral Energy, was last detected in the port on April 4.

Before, the tankers used to take several LNG cargoes every month from the plant with a capacity of 660,000 tonnes a year.

Advertisement: The National Gas Company of Trinidad and Tobago Limited (NGC) NGC’s HSSE strategy is reflective and supportive of the organisational vision to become a leader in the global energy business. ngc.co.tt

Gazprom Export, a subsidiary of Russian energy giant Gazprom , acts as the exporting agent for selling gas from the plant.

"Gasum has a long-term LNG supply contract with Gazprom Export and this contract is still valid," Gasum told Reuters. It also said the company obtained LNG from several different supply sources.

Most of the LNG purchased by Gasum comes from countries other than Russia, it added.

Novatek did not immediately respond to a request for comment.

Gazprom halted pipeline gas exports to Finland in May 2022, demanding that European countries pay for Russian pipeline gas supplies in roubles because of sanctions imposed over Moscow's actions of Ukraine, but Finland refuses to do so.

LNG supplies do not fall under the rouble payments scheme. (Reporting by Vladimir Soldatkin and Anne Kauranen Editing by Mark Potter)