The Irish Coast Guard has said technical tests were carried out on their helicopters today.

It followed calls by helicopter manufacturer Sikorsky for safety checks on all S92 aircraft worldwide after an incident on a North Sea platform.

A spokesperson for the Irish Coast Guard said the tests had been carried out and all helicopters were operational.

The incident on the oil platform on 28 December was caused by a damaged tail piston, an initial investigation has found.

The helicopter was landing on the West Franklin platform when it pitched to the side and left significant gouge marks on the deck, the Air Accidents Investigation Branch (AAIB) said.

Nine passengers and two crew were on board the helicopter at the time but no-one was injured.

The AAIB report said the helicopter "yawed rapidly to the right, reaching a maximum rate of 30 degrees per second" when it was 1.21m (4ft) above the landing platform, causing the landing gear to strike the deck.

It had "yawed unexpectedly to the right through 45 degrees" on an earlier departure but it was put down to turbulence at the time.

The AAIB said "it was immediately apparent that the tail rotor servo piston was damaged" when inspectors removed helicopter panels.

There were also signs of "severe overheating" and "extreme wear" on bearings.