The Civil Aviation Authority has contacted the manufacturer of the helicopter involved in a crash that seriously injured four people, including a bride and groom on their wedding day.
The helicopter crashed at Terrace Downs in Mid Canterbury on Saturday.
There were four people onboard - newlyweds Fay El Hanafy and Mahdi Zougub, photographer Rachel Jordan and the pilot.
All four suffered serious injuries.
They all remain in hospital.
The Civil Aviation Authority is investigating and confirmed to the Herald that it had contacted the company that made the helicopter.
"Our investigators have today contacted the helicopter and engine manufacturers [Robinson and Lycoming] requesting assistance with the investigation," a spokesperson said.
"We often work with manufacturers to help understand the cause of aircraft occurrences and accidents."
Yesterday a spokesman for the helicopter's owner Wyndon Aviation revealed the aircraft's engine lost power shortly after take-off - causing the Robinson R44 helicopter to crash.
"Although the investigation is still in its early stages, we have established the engine in the helicopter suffered a total power loss shortly after take-off," a spokesman said in a statement.
"Put simply the engine had stopped.
"Statistically this is a very rare occurrence."
Investigations into the crash had found no reason for the engine to lose power, the spokesman said.
The CAA spokesperson confirmed the reason for the crash.
"Early indications are that a total engine power loss did occur in flight, shortly after take-off.
"The reasons contributing to this power loss are still being investigated by our team, and this may take some time."
Representatives of Wyndon Aviation have met with the close family of the bride, groom and wedding photographer involved in the crash and told them about the engine's power loss.
"It is imperative we find the cause for the engine to have lost power," the company spokesman said.
"This accident will again raise the profile of the Robinson helicopter but it has to be remembered the power plant in the R44 is provided by a reputable third party manufacturer."
The pilot suffered "significant injuries to the hand, wrist, leg and back including broken bones and lacerations".
The spokesman said she was "not in a fit state to talk" about what happened.
There had been "some progress" in her condition but she was still seriously unwell.
Jordan suffered spinal fractures, five fractured ribs, a lung laceration, fractured sternum, a fractured arm and fractured feet.
Her husband Eric said she was worried her back was broken when they spoke on the phone just after the crash and before emergency services arrived.
"I heard ... a lot of screaming in the background that I assumed was the bride, and groom, and pilot, who had been injured as well," she told him.
"She told me she recalls the engine had shut off at some point, that it completely lost power in mid-air, and it seemed like the whole thing went dead."
The newlywed couple also suffered extensive injuries.
Their and Jordan's family had met at the hospital and "formed a bond", supporting each other through the difficult week.