Juan Tamad is a suspected gambling lord who is rumored to be enjoying protection from high ranking officials in the police and military. Through a tip from one of the confidential informant of our legislators, Juan Tamad was summoned to a hearing in the Committee on Other Syndicated Crimes of the House of Representatives, which was conducting a congressional investigation "in aid of legislation" on the involvement of police and military personnel, and possibly even of Mayors, Vice-Mayors or Governors in the illegal activities of suspected gambling lords. Subpoenaed to attend the investigation were officers of certain identified banks with a directive to them to bring the records and documents of bank deposits of individuals mentioned in the subpoenas, among them Juan Tamad. Juan Tamad and the banks opposed the production of the banks' records of deposits on the ground that no such inquiry is allowed under Republic Act No. 1405 also known as the Law on Secrecy of Bank Deposits. Is the opposition of Juan Tamad and the banks valid? Please explain.