UPDATED 6PM: An attempt to lift a 350 tonne piece of the Rena from the waters of Motiti Island has been struck by complications with salvors forced to lower the piece back to the sea floor.

The piece of the sunken stern section was cut from the ship at Astrolabe Reef earlier this week and dragged to the eastern side of Motiti Island where it was sitting in approximately 35 metres of water.

The RMG 500 barge working to lift a section of the sunken stern.

Spokesperson for the ship's owners and insurers, Hugo Shanahan, says after complications with the lifting chains and strong winds, during the third attempt to lift the piece of the accommodation block, it was decided to place the piece onto the sea floor.

This was after the first half section of the Rena accommodation house was successfully cut and removed from the stern section on Monday.

Hugo says during the lift operation and as the top half of the block started to clear the surface, the lifting chains, which are rigged through the house, started to tear through the starboard section.

'The chain eventually held steady at the bridge wing, with the port side remaining stable at around the E deck. The load was eventually stabilised, with the port side almost out of the water,” says Hugo.

'At this point, and with insufficient height for the lifting sheer leg to clear the load above the waterline and in the interest of safety, the decision was made to place the piece onto the sea floor.”

Resolve has since sought shelter from strong winds that immediately picked up after the cutting task, and while the cut piece was then hanging underneath the RMG 500 lifting barge.

Work is now underway to reset the starboard rigging before lifting can recommence.

A previous attempt to lift the piece on Tuesday night also failed after shackles in the rigging twisted.

The 350 tonne section is part of the accommodation or ‘house' block in the aft section of the 236 metre ship that sunk at the reef, about 25km off the coast of Tauranga, when it broke apart in early 2012. The ship grounded on the reef on October 5, 2011.