NEW DELHI, Feb. 14 (Xinhua) -- India's state-owned multinational banking and financial services company Punjab National Bank (PNB) Wednesday detected "fraudulent and unauthorised" transactions worth about 1.77 billion U.S. dollars at one of its branches in Mumbai.

"The bank has detected some fraudulent and unauthorised transactions (messages) in one of its branches in Mumbai for the benefit of a few select account holders with their apparent connivance," a company secretary in a communication to higher authorities of the bank said.

"Based on these transactions other banks appear to have advanced money to these customers abroad."

The bank however has withheld the names of the customers involved in the fraud.

"In the bank, these transactions are contingent in nature and liability arising out of these on the bank shall be decided based on the law and genuineness of underlying transactions," PNB said.

"The matter was already referred to law enforcement agencies to examine and book the culprits as per law of the land. The bank is committed to clean and transparent banking," PNB said.