Two experts have cast doubt over whether pilot Lance Hopping smoked cannabis in the hours before a fatal hot air balloon flight, at an inquest into the deaths of all 11 people aboard.
The second day of the inquest was held today before Coroner Peter Ryan at the Wellington District Court.
Mr Hopping and his 10 passengers were killed when the hot air balloon they were in became tangled in electrical wires, caught fire and crashed into a paddock, on a January morning in 2012.
A crash investigation by the Transport Accident Investigation Commission has established errors in judgment made by Mr Hopping ultimately caused the balloon's demise.
It also found he had cannabis in his system at the time of the accident, and impairment from the drug was unable to be ruled out as being a factor in his decision-making that day.
Forensic pathologist Fintan Garavan and ESR scientist Helen Poulsen gave evidence at the inquest today.
Samples taken from Mr Hopping, more than three days after the crash found 2 micrograms per litre of blood of the active ingredient in cannabis, THC, in his system.
Dr Poulsen said under normal conditions, that could indicate a cannabis cigarette was smoked up to five hours before death. But if smoked regularly, cannabis could accumulate in the body tissue.
In Mr Hopping's case, some decomposition of the sample and mixing of other bodily fluids could have increased or decreased the level of THC found in the testing.
"If he was a frequent user, then there would be a possibility that THC stored in the body could have increased the level found," she said.
Continued below.Related Content
Watch NZH Local Focus: 'We were likely to be blamed for the contamination'
Your Views: Readers' letters
Sideswipe: May 12: Not very sensible
Earlier today, Mr Hopping's friend Bruce Miller told the inquest Mr Hopping was a frequent user and smoked about once a week.
Dr Garavan said that amount of use was sufficient to build up the THC levels in Mr Hopping's body.
Once a user stops smoking, the amount of THC can build up in the blood system as the drug, which had accumulated in the body tissue over a long period of time, was released into the body, he said.
"It is an absolute certainty that on the day you stop smoking I will find THC acid in your urine."
The evidence supported Mr Hopping being a chronic user, not that he had smoked that morning, Dr Garavan said.
There was also no evidence of cannabis smoke in his lungs, which there would have been if he had smoked on the morning of the flight, he said.
"It's highly unlikely that he smoked that morning."
This morning, photographer Geoff Walker, who took about 700 photographs on the day of the flight said he had never seen Mr Hopping smoke before takeoff, and he did not smoke tobacco.
Yesterday the daughter of two of the victims, Bronwyn Brewster, told the inquest she had seen Mr Hopping smoking on the morning before the flight, but she did not know what he was smoking.
The inquest, which has been set down for four days, continues.
- APNZ