Conn. Gen. Stat. § 12-39f
Sec. 12-39f. Refund of state taxes. Limit on interest added or awarded.
(b) Notwithstanding any provision of law, interest added to a refund of tax issued by the Commissioner of Revenue Services for a tax period shall not exceed five million dollars and no court may award interest in excess of five million dollars in any tax appeal in connection with a claim for refund of tax for a tax period.
See Sec. 12-39w re prohibition and time limit applicable to refund claims.