Large swells had broken up the Austro Carina fishing boat at Red Bluff near Shell Bay.
Environment Canterbury said 10,000 litres of diesel had slowly dispersed over the past week and up to 400 litres of hydraulic oil could also be leaking from the engine room, but crews could not reach it to check.
Salvage teams had so far picked up 31 large bags of rubbish, debris and fish bins.
Fishing nets had also been removed from the vessel, aside from some that were unable to be cut away from under the stern.
The wreck had broken up significantly and had moved up the beach to the north.
The council said the cleanup would be ongoing, because there was still loose debris on the beach, with more expected to be released from the wreck as it broke up.
On Thursday it had observed no signs of oil on the surface of the water, or oiled wildlife.
Maritime New Zealand and the Transport Accident Investigation Commission are investigating the incident.
