The Ngai Tahu Tourism boss says arborists have been to check all the trees at Shotover Jet's base after five people were hurt when a large willow toppled in the wind yesterday.
Chief executive Quinton Hall says it isn't immediately clear whether Ngai Tahu Tourism - which operates the jet - is responsible for maintaining the willow, or the Department of Conservation, which owns the land.
Three people remain in hospital after being crushed when the tree came crashing down on to the picnic table where they were sitting just before one o'clock yesterday afternoon.
The other two have been discharged.
Mr Hall says the company will assess its policies and protocols in light of the incident.
A decision on reopening the Shotover Jet is expected later today.
A mother and her son were critically injured when the tree fell, but they're now in a stable condition.
The pair were visiting from Wellington.
Bystanders lifted the tree off the five people who were sitting underneath it when it fell about 1pm.
Of the three people remaining in hospital, one child is in a serious and stable condition and an adult and a child are in stable conditions.
All the victims were conscious when emergency services arrived on the scene.
The victims were mix of foreign nationals and New Zealand citizens, but all were residing in New Zealand, police said.
RNZ reporter Tim Brown told Morning Report when he arrived at the scene emergency services had already left and that the felled tree had been significant in size.
"What was apparent was just the size of this tree, it is massive. It's a surprise that anyone walked away from this, let alone all five according to reports, were still conscious at the scene," he said.