No person is excused from attending and testifying or from producing any document or record before the securities commissioner or in obedience to the subpoena of the securities commissioner or any officer designated by him or in any proceeding instituted by the securities commissioner, on the ground that the testimony or evidence, documentary or otherwise, required of him may tend to incriminate him or subject him to a penalty or forfeiture. But no individual may be prosecuted or subjected to any penalty or forfeiture for or on account of any transaction, matter or thing concerning which he is compelled, after claiming his privilege against self-incrimination, to testify or produce evidence documentary or otherwise, except that the individual testifying is not exempt from prosecution and punishment for perjury or contempt committed in testifying.