Fishing company Sanford Limited is facing three charges under the Maritime Transport Act for allegedly dumping oil in New Zealand's Exclusive Economic Zone from the Korean foreign charter fishing vessel Pacinui.
Maritime New Zealand laid the charges after an investigation discovered the alleged illegal dumping.
The company was with illegal discharge of a harmful substance, failing to notify Maritime NZ of the discharge, and failure to notify a pollution incident.
The discharge of a harmful substance charge carries a maximum penalty of two years imprisonment or a fine of $200,000.
The two other charges each carry a maximum fine of $100,000, and for a continuing offence, a further fine not exceeding $20,000 per day or part day the offence is committed.
The charges follow an extensive investigation started by Maritime NZ in January - which included examining the ship in Timaru, gathering photographic and video evidence, forensic examination of the samples, and interviews with a number of Indonesian crew members.
The case is due to be called for the first time in Timaru District Court on August 26.