The Commission may refuse to excuse any person from testifying, or from producing books, records, correspondence, documents or other evidence in obedience to the subpoena of the Commission notwithstanding an objection that the testimony or evidence required of him may tend to incriminate him. No individual shall be prosecuted in any manner or subjected to any penalty or forfeiture whatever for or on account of any transaction, act, matter or thing concerning which he is compelled, after having claimed his privilege
against self-incrimination, to testify or produce evidence, except that the individual so testifying shall not be exempt from prosecution and punishment for perjury committed in so testifying. No immunity shall be granted to any witness under this section unless the Commission has notified the Attorney General of its intention to grant immunity to the witness at least thirty days in advance, or unless the Attorney General waives this requirement.