"It is quite possible that the [agreement] may be reopened as a result of the bank's activities on either or both the tax evasion and foreign exchange manipulation front," the official, who declined to be named, said.

Under the terms of the 2012 agreement, HSBC was obligated for five years to both fully cooperate with prosecutors on any other investigations and commit no crimes after it signed the deal.

(Reporting by Aruna Viswanatha; Editing by Sandra Maler)