Salvors are removing containers and cargo from the sunken stern section of the Rena wreck on the Astrolabe Reef.

Svitzer salvors have used wire ropes to secure the Smit Borneo crane barge to the port quarter of the wreck.

The Smit Borneo has begun container lifting operations from the sunken stern section of the Rena wreck. Photo: LOC.

It is positioned to enable salvors to work the aft holds and seafloor in the immediate vicinity of the barge.

With this method at the weekend the salvors removed eight containers from the sunken section.

There are still containers on the bow section of the wreck and salvors are continuing to cut and grind them, with assistance from helicopters to remove debris.

Container salvage contractor Braemar Howells has received a total of 491 containers from the Rena, and recovered another 70 from the sea/beaches.

A further 17 have been located which are still to be recovered.

This brings the total either recovered or located to 578 out of the original 1368 onboard when the Rena ran aground at the reef on October 5.

Maritime New Zealand estimates about 250 containers are below decks in the forward section of the wreck.

However, due to the significant damage to the vessel and containers, MNZ says it is impossible to gain an accurate count of exactly how many remain onboard.

The condition of the wreck continues to deteriorate with electronic sensors showing there is a noticeable heave and roll on both the bow and stern sections.