Toddler critical after two kids fall from wharf near Great Barrier Island

A major emergency response is currently underway off Great Barrier Island after two children fell off a wharf.

St John Ambulance confirmed the incident involved two toddlers - an 18-month-old boy and a 3-year-old girl, who fell into the water at the isolated Rangiahua Island. Emergency services were alerted to the incident at 7.46pm tonight.

The 18-month-old boy was in critical condition at Starship Hospital as of 11pm, an Auckland District Health Board spokeswoman said.

The 3-year-old girl was in stable condition as of 11pm, the spokeswoman said.

One patient required CPR, a police spokesman confirmed.

Both children were being stabilized on the island before being airlifted to Starship children's hospital in separate rescue helicopters.

The young boy remains in a critical condition but is on route to Starship. The girl is also being airlifted to Starship in a moderate condition. Both rescue helicopters have intensive care paramedics onboard, a St John spokeswoman said. No further details were available, other than that it was a "water incident".

A staff member at Aotea Health Centre, on Great Barrier Island, acknowledged she knew about the incident, but declined to comment further.

A Westpac Rescue helicopter from Auckland and a Northland Emergency Services Trust (NEST) helicopter from Whangarei attended the incident.

Both rescue choppers landed at Starship about 10.20pm.

An eyewitness saw the young girl being lifted out of the chopper by a man who carried her into the hospital wrapped in clothing and wearing a beanie.

A spokesman at the NEST office said its helicopter appeared to have carried out a search of the waters.

The NEST spokesman said the helicopter had attended another incident of a person falling off the Rangiahua Island wharf about a year ago.

Emergency services were called out to Rangiahua Island. Photo / Daniel Hines

A man had been painting his boat when he fell off, the spokesman said.

A Police spokesman said St John Ambulance were taking the lead on the incident and officers were not in attendance.

A northern fire communications spokesman confirmed two children had fallen off a wharf on the remote island.

Emergency services responded from the Auckland Marine Rescue Centre at Mechanics Bay.

MetService meteorologist Derek Holland said there had been light to moderate south west winds and a few showers at Great Barrier Island tonight.

It was about 20C at the island, he said.

A Great Barrier Island resident who has relatives living on Rangiahua, which is just off the west coast of Great Barrier, said a small handful of families lived on the island but the numbers fluctuated with the time of year.

In 2014 the Herald reported there were only 15 or so residents on the isolated island.

More information to come.