The grounded boxship Kea Trader has broken in two on a reef off New Caledonia.

Owner Lomar Shipping told TradeWinds four months of "continual pounding in sometime storm-force seas and the stress of sitting hard aground a flat rock reef" resulted in the 2,194-teu vessel (built 2017) fracturing vertically over the weekend.

"Noticeable vertical buckling in the mid-section of the hull side expanded during violent six-metre waves, causing the vessel to rupture completely into two halves on Sunday," it added.

Each piece remains in situ, although the break-up and heavy seas resulted in two container units falling into the water.

They are being monitored, as is the vessel itself, by two tugs that remain on site, along with specialist anti-pollution contractors.

Ahead of the latest bout of poor weather, all but a skeletal team of nine Ardent workers had been removed from the vessel last Thursday – the fourth such time that crew and salvage personnel were taken off as a precautionary measure, Lomar said.

The remaining nine Ardent salvage workers were all airlifted safely off by helicopter on Sunday.

A total of 108 containers out of an original cargo of 756 units were still on board.

A Lomar spokesman said: “Damage to the vessel has increased with every month that she has been hard aground.

"A noticeable buckling in the hull side developed following an unsuccessful re-floating attempt at the beginning of October, along with other clear damage to the bottom of the vessel.

"Whilst this has all been closely monitored and assessed by specialist structural engineers, a heavy storm at the weekend added substantial additional stress and caused the ship to split into two. We remain committed to removing the vessel whilst also ensuring that the marine environment is protected and will be working with our partners to ensure this is realised.”

Kea Trader grounded on 12 July en route from Papeete, in French Polynesia, to Noumea in New Caledonia.

A rare ideal weather window and high tide allowed recovery teams to attempt an accelerated refloating operation in early October.

But this failed to dislodge the vessel and merely pivoted it by 60 degrees, with the rudder remaining firm in the same position. Four-fifths of the hull is sitting on the hard rock reef.