Japan's central bank on Tuesday became the latest organisation to express concerns over the access journalists at Bloomberg News have had to potentially sensitive data.
The Bank of Japan's comment comes as a scandal grows for the financial news wire, whose terminals are used every day by officials at many of the world's most important institutions and banks.
"We are now in contact with Bloomberg's office in Tokyo to determine the facts," said a BoJ spokesman, adding that he hopes Bloomberg will make a formal announcement about the facts as "its responsibility to clients."
Bloomberg has already apologised for an "error" that allowed its journalists to see client data. One report said the system allowed access to the accounts of US Federal Reserve chairman Ben Bernanke and former Treasury Secretary Timothy Geithner.
The Fed said Monday it had asked Bloomberg News for information on whether its journalists were inappropriately allowed to see client data.
The US Treasury Department also was "looking into the matter," a source familiar with the matter, told AFP in the US.
CNBC reported Sunday that a former Bloomberg employee acknowledged that he accessed usage information of Bernanke and Geithner.
Bloomberg announced Friday it was curbing reporter access to certain data on its financial terminals after reports claiming its journalists used the devices to spy on Wall Street banks.
The New York Post reported Friday that Goldman Sachs confronted Bloomberg over concerns that reporters at the news service had been using the financial information terminals to keep tabs on employees of the bank.
According to the report, Goldman found Bloomberg staffers could determine which employees had logged into Bloomberg's proprietary terminals and how many times they had used particular functions.
A separate report by the Financial Times said JPMorgan Chase had also complained that Bloomberg reporters were spying on activities by bank employees.
The Bloomberg financial terminals, which are operated separately from the news service, give banks and other financial professionals the ability to research virtually any type of financial asset and carry out trades.
A rival of Thomson Reuters, Bloomberg was founded by New York Mayor Michael Bloomberg, who is not involved in management due to his political activities.