The pair were arrested by police last week in connection with what police say is the
largest-ever seizure of methamphetamine in the South Island.
The drugs arrived into Christchurch in an airfreight consignment sent from Mexico on November 1, police say.
Detailed examination found 49kg of methamphetamine concealed within a shipment of safety lights.
It consisted of 40 separate packages of around 1-1.2kg each, which has yet to be further forensically examined to determine the exact weight of the product.
Police say the drugs had a potential street value of $50m, and the seizure has prevented $60.71m of "additional community harm".
Search warrants were executed at a number of addresses in Christchurch and in Auckland after a two-week joint police and Customs operation.