Russian lender Gazprombank has decided to freeze the accounts of Venezuela's state oil company PDVSA whose subsidiary, PDV Caribe, controls 49 per cent of Petrojam.
It has also halted transactions with the firm to reduce the risk of the bank falling under U.S. sanctions.
A Gazprombank source confirmed the move in an interview with Reuters yesterday.
According to Reuters, while many foreign firms have been cutting their exposure to PDVSA since the sanctions were imposed, the fact that a lender closely aligned with the Russian state is following suit is significant because the Kremlin has been among Venezuelan President Nicolas Maduro's staunchest supporters.
PDVSA brandished the story as fake news on its Twitter account in capital red letters, but did not reply to a request for comment.
Reuters reported this month that PDVSA was telling customers of its joint ventures to deposit oil sales proceeds in its Gazprombank accounts in a move to try to sideline fresh U.S. sanctions on the Venezuelan oil firm.
Washington says the sanctions, imposed on January 28, are aimed at blocking Maduro's access to the country's oil revenue after opposition leader Juan Guaido proclaimed himself interim president and received widespread Western support.
Gazprombank is Russia's third biggest lender by assets.
The bank has held PDVSA accounts for several years.