Prime Minister John Key has expressed his condolences to the family of a British man killed in a Fox Glacier plane crash, but says the adventure tourism industry is sound.

Bradley Coker, 24, was killed alongside eight others when the Fletcher FU24 aircraft operated by Skydive NZ crashed at Fox Glacier, South Westland, on September 4 2010.

A Transport Accident Investigation Commission report found that at least two of the tandem-master crew who would accompany the skydivers in the aircraft had taken controlled drugs and one had taken cannabis during that day's operations.

The report was critical of the Civil Aviation Authority which it said did not do enough to monitor the safe operation of the company and called on the government to introduce testing for drugs and alcohol.

Mr Coker's father, Chris, has written to Mr Key, urging him to review the industry.

In his letter, Mr Coker said the circumstances that led to his son's death "are a shocking catalogue of behaviour that would be regarded as negligent in every civilised country in the world".

Mr Coker says until regulation, inspection and control of adventure sports, particularly involving aircraft, is "radically tightened", he would advise people to think twice before visiting New Zealand for adventure sport.

Mr Key said Bradley's death was "very tragic" but the vast majority of tourism operators were safe.

He had launched a review of the industry in 2009, following the riverboarding death of British tourist Emily Jordan, whose father, Chris, also wrote to Mr Key seeking action.

"As a result of that, a number of changes were made that would have prevented, arguably, the accident at Fox Glacier, and that's been very, very important that that's happened. We have incorporated most of those," Mr Key said.

"...I've instituted changes which will ensure that they'll be ... safer, and I think they (the grieving parents) can take comfort from the fact that for the most part they should be OK."