Maritime New Zealand says salvors onboard the container ship Rena are concerned about worsening buckling where the vessel hangs over deeper water.
MNZ says pumping of oil from the vessel, which is stranded on a reef off Tauranga, to a bunker barge resumed on Friday afternoon.
Salvage unit manager Bruce Anderson says the buckling appears to be getting worse regardless of the weather and is being monitored daily. He says it is occurring gradually.
He says salvors have temporarily abandoned efforts to drain a submerged passageway to reach the last remaining tank containing heavy fuel oil, after divers found a barrier to contain the water had been destroyed.
Two hot tap systems will now be set up to extract oil, but at a slower rate, from the submerged tank.
Oils and lubricants from the stricken vessel have been transferred to a central tank in the engine room and from there are being pumped to the barge.
Maritime New Zealand have also revealed a salvor injured his wrist on the Rena on Friday, when he slipped in a corridor.
He has been taken off the vessel and the injury is being assessed.
