No person so subpoenaed or ordered shall be excused from attending and testifying or from producing books, records, correspondence, documents, or other evidence on the ground that the testimony or evidence required of the person may tend to incriminate the person or subject the person to a penalty or forfeiture; but no person shall be prosecuted or subjected to any penalty or forfeiture for, or on account of, any transaction, matter, or thing concerning which the person is compelled, after having claimed the person's privilege against self-incrimination, to testify or produce evidence, except that such person so testifying shall not be exempt from prosecution and punishment for perjury committed in so testifying.
Iowa Code § 97B.24
Perjury, §720.2