A woman who was suspected to have broken her leg in a jet boating accident in Queenstown yesterday remains in hospital, and a investigation into the cause of the crash continues.

Ten people were on board the Skippers Canyon jet boat when it crashed into rocks while riding the Shotover River just after 10am yesterday.

Skippers Canyon Jet marketing manager Gavin Larsen said this morning the woman and one other passenger remained in hospital, and the remaining passengers had been discharged yesterday.

"Six passengers have now been treated for minor injuries and discharged, while another two are being held for observation.

"One passenger has been transported to Dunedin Hospital with a broken limb. The boat driver suffered minor injuries but did not need medical treatment," a Skippers Canyon Jet statement said.

The driver was doing "really well", Larsen said.

"He was able to help out directly after the crash and then with Maritime NZ inquiries yesterday.

"He was then taken to hospital yesterday evening just for precautionary measures, but by all accounts he is doing really well."

Larsen said the adventure company's operations remained suspended until further notice while a Transport Accident Investigation Commission and Maritime NZ investigation took place.

Investigators are yet to determine what caused the crash.

"The company followed its operational safety procedures as a result of the incident and is working alongside the Maritime Safety Authority to determine its cause. A team from the TAIC will arrive in Queenstown tomorrow," the statement said.

Larsen said the company would conduct its own internal investigation and would fully co-operate with the relevant authorities.

"We deeply regret the distress caused to all passengers involved and are providing them with our full support," he said.

The rescue helicopter team was called in yesterday morning to airlift nine patients after the jet boat crashed on a remote part of Queenstown's Shotover River.

The group were roughly halfway through the trip down the river when the incident occurred.

Several passengers were part of a group of tourists from Thailand. Two others were Canadian tourists - one, a middle-aged woman, was suspected to have a broken leg.

Otago Rescue Helicopter Trust's chief pilot Graham Gale said his team were called in to transport patients from the spot, which was tricky to access.

"There is no road - there is no road access to where we picked them up from," he said.

The team made two trips transporting patients to Lakes District Hospital. The Canadian woman with the injured leg was transferred to Dunedin Hospital shortly after.

Gale had not assisted in the rescue but said the patients were agitated.

"You're in an incident like that ... everyone is always distressed to a certain level when they're involved.

"We're quite focused on doing what we do - we go in there and we do the business, get them out, and get them away to hospital."

A witness at the scene said the accident appeared to have happened about 200m downstream of the Skippers Canyon suspension bridge.

"It looks like it was a substantial accident."

The witness said it was a beautiful, hot day in Queenstown, with a bit of cloud overhead.

Queenstown Lakes District Council Mayor Jim Boult said jet boat rides on the Shotover River were immensely popular with tourists.

"Jet boating is synonymous with Queenstown. I couldn't tell you exact numbers but I'd imagine an excess of a couple of hundred thousand people a year would undertake one of the activities on the river."

Boult said his first concern was for those involved.

"I'm sure the appropriate bodies are looking after the welfare of those people.

"The second concern is to ensure the accident is thoroughly investigated - I'm sure we'll run a very thorough investigation into that."