Two people are dead and three children are injured after a helicopter crashed north of Kaikōura today, with a witness seeing it "fall out of the sky".
In a statement police say emergency services are responding to the scene on a beach near the Kekerengu River mouth.
Police say five people were on board, including the pilot.
St John told 1 NEWS two helicopters and one ambulance have arrived at the scene.
A Transport Accident Investigation Commission spokesperson says the three injured survivors were children and they have all been airlifted to Christchurch Hospital, where one is in ICU. 1 NEWS understands the aircraft's passengers were a family from Kaiapoi.
The two people who lost their lives were both adults.
Investigators from the Transport Accident Investigation Commission are flying down to the scene tonight.
"Further details regarding the deceased and injured, including ages and genders, will not be released until all necessary family notifications have been carried out," police say.
The Transport Accident Investigation Commission says the Airbus Helicopter EC120 was travelling from Christchurch with five persons on board when it lost control, descended and impacted shallow water close to the beach.
Ian Mehrtens, owner of Coastal Lodge, says he “saw it fall out of the sky” and it was “pretty scary” to watch.
He says it landed on the beach and three children were on board.
"I saw a helicopter coming in to land and saw it about 30 or 40 metres off the ground, then all of a sudden it went into a spin, round and round then it dived," he told 1 NEWS.
"I didn’t see it hit the ground but I went over to see if I could help and it was a bit of a mess — bits and pieces everywhere."
Mehrtens say he and a few other locals helped pulled them out.
Around five or six locals and tourists were the first on the scene before emergency services arrived.