The stricken container ship Rena is facing three metre swells this morning but Maritime New Zealand confirms there is no reported change to the vessel overnight.

The salvage support vessel Go Canopus remains near the 47,000 tonne ship grounded on the Astrolabe Reef, monitoring the situation hour by hour.

Deteriorating weather with five metre swells is threatening the Rena grounded on Astrolabe Reef.

Salvors working to pump the ship's fuel off the wreck were removed yesterday due to deteriorating weather conditions.

The weather at the reef is forecast to further deteriorate in the next 24 hours, with a sea state of up to five metre swells anticipated.

The Rena has large cracks on both sides of the hull about 70 metres back from the bow. The bow section is supported by the reef where it is hard aground, but the stern is over deep water.

There are fears the wave action by the storm swells may break the weakened ship in two, or dislodge more containers.

The Rena had 1368 containers on board at the time of grounding. The storm two weeks ago dislodged 88. Initial reports were that 20 or so were unaccounted for, but that has been revised to 58.

An observation flight took place earlier today and Maritime New Zealand will know more when it returns later.

MNZ spokesman Ross Henderson says a further update will be issued once more information becomes available.