The Bank of Japan said it had contacted Bloomberg LP after the financial data and news company allowed journalists to see some information about how clients used Bloomberg terminals.
"We are now contacting Bloomberg and are in the process of confirming the facts of the situation," a spokesman for the Bank of Japan, the country's central bank, told Reuters.
The Hong Kong Monetary Authority, the territory's defacto central bank, added: "We are aware of the reported incident and are looking into the matter."
The HKMA did not say if it had contacted Bloomberg.
The European Central Bank, Brazil's central bank and the U.S. Federal Reserve have all said they were looking into any possible breaches in the confidentiality of usage data related to Bloomberg terminals.
Bloomberg has said its journalists until recently had "limited" access to data about how clients used their Bloomberg terminals. Matthew Winkler, editor-in-chief of Bloomberg News, apologized for the practice on Monday, saying it had been "inexcusable" but that important customer data had always been protected.
(Reporting By Sumio Ito; Editing by Dean Yates)