Prosecutors on Friday asked the Tokyo High Court to fine 23 bridge builders and imprison eight former senior officials accused of rigging bids for bridge construction projects financed by the now-defunct Japan Highway Public Corp. and by the Land, Infrastructure and Transport Ministry.

The prosecutors, in their closing arguments, denounced the defendants, saying they inflated bridge construction costs through the bid-rigging and caused the highway operator and the ministry to lose a combined 10.2 billion yen in fiscal 2003 and fiscal 2004.

The 23 corporate and eight individual defendants have pleaded guilty at the Tokyo High Court to charges of violating the Antimonopoly Law.