A ceremony to hand back 175 kilograms of contraband pounamu, or greenstone, to Ngai Tahu was held in Christchurch, marking International Customs Day on Thursday.
Representatives of Ngai Tahu and Customs attended the ceremony at Rehua Marae.
A Customs deputy controller, Robert Lake, says the pounamu was intercepted in December 2010 but its return was delayed by the earthquakes and the need to verify where the stone came from.
Mr Lake says the pounamu, which was being exported by a jeweller to a customer in China, was one of the most significant amounts seized in his six years with the department.
He says it was seized after it was found the jeweller did not realise a permit is required to export pounamu over 5 kilograms.