The parents of a Sydney schoolboy killed while skiing in Austria say the avalanche that buried their son was triggered by a ski patrol trying to rescue the family.

Key points: Max Meyer died while skiing off-piste with his family in Austria last week

Max Meyer died while skiing off-piste with his family in Austria last week In a statement the family said they were trapped but uninjured before rescuers arrived

In a statement the family said they were trapped but uninjured before rescuers arrived The family said they were "engulfed" by the avalanche

Max Meyer, 16, his younger brother and parents had been skiing off-piste at St Anton am Arlberg when the avalanche buried him in two metres of snow.

The International Grammar School student was trapped for 20 minutes and was unable to be revived.

His parents Thomas Meyer and Julie Schatz said in a statement that the avalanche occurred after they became stuck while skiing in a narrow valley between two main runs.

"Due to the depth of the snow, we considered it safer not to try to walk out, but to contact the ski patrol for advice and so that they would know our location," the statement said.

Ski patrol told them to stay where they were and await rescue.

"At that point in time, we were uninjured, and in no immediate danger," they said.

"In the process of the ski patrol trying to reach us by skiing down from above us on the opposite side of the valley, an avalanche was triggered which engulfed us and tragically led to the death of our son Max."

The family had been skiing off-piste in a narrow valley between two main runs. ( Facebook: Bergrettung St.Anton am Arlberg )

The couple said they were grateful for the support of Austrian authorities and the "best efforts" of rescuers to resuscitate Max.

The Coroner confirmed their son's death had been "instant and painless", they said.

"We can find no words to express how much and how deeply Max was loved by us, and by so many others," they said.

"Whilst this is obviously a profoundly difficult time for us, the support from our family and friends and from the International Grammar School community has meant a great deal."

St Anton mountain rescue manager, Kurt Huettl, called for patience while the rescue and death were being examined.

"The incident is still being investigated by the authorities, so we need to be patient - at the moment we really can't say anything," he said.

Last week, Patrick Wechner from St Anton's Mountain Police told the ABC the rescue effort had involved 45 people and a rescue dog.

Conditions had been "difficult…[on] the one hand because there was a risk of avalanches, on the other hand because of the terrain".

"Above the accident site there were still masses of snow and there was a danger that something further could happen."

Mr Wechner said it was the first avalanche they had had so far this season in the area, and although there was a large amount of snow it was "completely normal" for the time of year.

With AAP