The Government needs to consider mandatory drug testing in the tourism industry following revelations of drug use in two air tragedies, Prime Minister John Key says.



The pilot of a hot air balloon that crashed in Carterton in February, killing 11, had cannabis in his system, as did two skydive masters who died in the 2010 Fox Glacier plane crash that claimed nine lives.



Toxicology tests performed on the body of Lance Hopping, 53, four days after the Carterton ballon crash, returned positive for cannabis, with the discovery described as "concerning" by investigators.



Civil Aviation Authority chief executive Graeme Harris said he was "disappointed" by evidence of cannabis use in the crash and the Fox Glacier crash.



Cannabis had not been shown to be a direct factor in either crash.



Speaking at a tourism conference in Queenstown today, Key said tourists had to have a high degree of confidence in operators.



Key, the tourism minister, said mandatory drug testing had been introduced in indusries like engineering and forestry.



"As a government we need to go away and see if there's more we can do in terms of the tourism sector.



"In my view its totally unaccepatable to have people working in the adventure tourism industry with significant drug and alcohol in their system - we need to solve that issue, and we're going to go away and see how we can achieve that," he said.

Taupo sky dive operator John Funnell said mandatory drug tests for tourism operations is appropriate.

"Recreational drugs have no part in commercial tourism aviation - full stop," Funnell said.

Funnell is managing director of Taupo Tandem Skydiving - one of the biggest skydive operations in Australasia.

"We would have no issue with mandatory drug testing - we have been doing it for years," he said.

"All our employees who work in the drop zone are already subject to random drug testing as a requirement for the provision of a safe workplace."

Since the balloon accident new rules covering the commercial ballooning sector had been introduced demanding higher standards from operators who wished to carry fare-paying passengers.

And Key today said quicker application of CAA rules regulating the aviation industry would have ensured the Fox Glacier crash did not happen.

"Any death is one too many,'' he said. "There are risks inherent in any adventure tourism activity, and this true around the world, but I believe that if CAA's part 115 been in operation sooner, this tragic crash would not have happened.''

Part 115 is a new certification regime for commercial adventure aviation that was introduced on May 1 and regulates hang-gliders, paragliders, ballooning, tandem parachute jumps, microlights and gliders.

Other operators are being regulated by new Labour Department rules brought about by a review of the adventure tourism sector initiated in 2009.

The review was prompted by British father Chris Jordan, who wrote to Key after his daughter Emily drowned while riverboarding on the Kawerau River in 2008.

Under the review's rules operators will be audited at least every three years, replacing the previous system of voluntary audits.

Audits of about 400 adventure tourism operators began this month but will take three years to complete.

Chris Coker, father of English tourist Bradley Coker, who died in the plane crash, has written to Key asking for answers.

Press reports quote the family as saying the New Zealand's adventure industry was far from safe.

Key said he sympathised with Coker as a parent, but as a politician disagreed that New Zealand's adventure industry was unsafe.

"I take Mr Coker's loss and grief very seriously but my fundamental view is that the industry is safe, especially after the elimination of one or two rouge operators from the industry.''