The Civil Aviation Authority has completed an initial investigation of maintenance practices for hot air balloons and says one company will be scrutinised further.
Concerns about the maintenance of New Zealand's hot air balloons were raised during the Transport Accident Investigation Commission's inquiry into a fatal accident in Wairarapa on 7 January this year.
Pilot Lance Hopping, of Masterton, and 10 passengers died when the balloon hit power lines and caught fire before plummeting to the ground near Carterton.
Investigators contacted all five active hot air balloon maintainers to seek assurance that safety standards are being met.
The CAA says in most cases, it has been satisfied that practices are at or above the required minimum safety standards.
The authority's director, Steve Douglas, is confident there is no culture of complacency in the industry.
"The investigation has shown largely, in the great majority of cases, that the maintenance of balloons has been carried out in a professional and fully compliant way."
Mr Douglas says that in one case, however, not all maintenance practices have been followed by the company according to the required standard.
The company and the 16 balloons it maintains will undergo further investigation.