It shall be the duty of the Police Department to provide such assistance as the Board may reasonably request, to cooperate fully with investigations by the Board, and to provide to the Board upon request records, personnel and other materials which are necessary for the investigation of complaints submitted pursuant to this section. Upon a finding by the Board that documents or personnel requested have not been forthcoming or that witnesses and documents outside City control must be produced, and that necessity requires the exercise of the Managing Director's powers under Charter Section 8-409, the Board may issue subpoenas for such witnesses or documents as it may deem appropriate; provided, however that no document or information obtained through formal or informal process under any section of this Chapter, or created by the Board or any member of its staff, shall be released to the public unless such document is deemed by the Board to be a public record under the Pennsylvania Right to Know Act, 65 P.S. 66.1, et seq.