The cyclists, along with the tractor driver, were regarded as key witnesses to the inquiry.
The Department of Conservation has taken over the fire-fighting efforts.
The wind, which fanned the fire on Monday, remained light yesterday and firefighters kept it from spreading any further.
However, DoC fire technical support officer Craig Alexander said it had still not been contained.
Chiefs are preparing to get ground crews mopping up its perimeter, he said.
But the conditions are difficult.
"It's steep, ugly conditions," he said. "One hectare scrub fires can be challenging, let alone scrub, beech forest, wilding pine, patch fields, where you are in and out, and the firefighter risk is quite high."
Crews have been brought in from the North Island, Otago and Southland to give their Canterbury comrades some respite.
Canterbury crews are also staying on call in the region, which is tinder dry and on high alert.
