March 12 (Reuters) - The U.S. government's four-part system for refunding $166 billion in illegal tariff payments with interest is between 40% and 80% complete, according to a court filing on Thursday from a top customs official.

Brandon Lord, an official with U.S. Customs and Border Protection, said the agency is developing a four-part system it calls CAPE that will accept refund claims, mass process them, review them and issue refunds, according to a court filing.

Lord's filing in the U.S. Court of International Trade was made to comply with an order issued last week by Judge Richard Eaton as part of his directive to refund tariff payments.