Two New Plymouth men survived a helicopter crash in the South China Sea at the weekend.

Jim McDowall, 50, and Mark Birdsall, 34, were in a helicopter that was heading for an oil rig off west Borneo when it plunged 100m into the sea.

They were able to scramble clear of the aircraft and floated in their lifejackets until they were rescued by the oil platform's standby vessel.

Shell Malaysia said none of the 11 passengers or two pilots were seriously hurt in Saturday's crash.

"It was the hand of God that saved them all," Mrs Joce McDowall said last night after speaking to her husband. "He's fine - it's miraculous."

Mr McDowall worked for the New Zealand-based Shell Todd Oil Services for more than a decade and has three children.

Mr Birdsall, a former soldier, is married with one child. He has worked for Shell Malaysia for three years and has had rigorous training in helicopter safety procedures.

The men were taken from the B-11 platform by helicopter for a checkup at a hospital near Sarawak, said company general manager Paul Zealand.

"They are well cared for and have New Zealand colleagues with them," he said. "We're delighted they got out safe and well."

Mr Zealand said Shell Malaysia had ordered an investigation into the midday crash of the Malaysian Helicopter Service's Super Puma aircraft.

Associated Press quoted one of the eight Malaysian survivors, Rowin Nayon, as saying the helicopter had technical problems about 96km into the flight from Miri helibase in Borneo.

It was only 200m from the drilling platform when it went down.

There was panic in the cabin and Mr Nayon said he did not think they could save themselves.

"We are so thankful that the helicopter did not explode."

A British passenger, Dennis Lloyd, said everyone was able to get out within minutes after the helicopter plunged into the sea.