Hong Kong's de facto central bank said it is investigating possible misconduct by UBS and HSBC over its submission of interbank rates. REUTERS/Tyrone Siu

Looks like Hong Kong’s de facto central bank could use an Edward Snowden type at some of its commercial underlings.

The Hong Kong Monetary Authority, or HKMA, said Tuesday that its investigation into possible manipulation of the Hong Kong Interbank Offered Rate, or Hibor, has broadened to include HSBC Holdings PLC (HKG:0005) and other banks, Reuters reported.

The HKMA already announced in December that it was probing UBS AG (NYSE:UBS) for possible misconduct with the benchmark rate.

“Apart from UBS, the HKMA have since December 2012 followed up with a number of banks including HSBC (both local and international banks) to ascertain whether there have been any inappropriate market conducts in their benchmark rate submissions,” HKMA said in a statement.

The London Interbank Offered Rate, or Libor, was notoriously rigged last year. On Tuesday, Tom Hayes, a former UBS and Citigroup Inc. (NYSE:C) derivatives trader, was charged with eight counts of conspiracy to defraud, the U.K. Serious Fraud Office said.