Banco Bradesco SA has received a subpoena from the general internal affairs of Brazil's ministry of finance as part of the so-called "Operação Zelotes" tax and bribery case, the bank said in an April 5 filing.

The procedure intends "to establish any administrative practice of acts against the public administration," Bradesco said, noting that the subpoena will allow it "to accompany all supporting acts of the prosecution."

The bank has been under investigation for purportedly hiring a group to pay bribes to government tax officials in exchange for writing off corporate tax debts, previous reports said.

In the filing, Bradesco reiterated that "it has not realized any proposal, hiring or payment to anyone, for any kind of advantage in the Administrative Council of Tax Appeals (CARF)."