The head of the Pike River Recovery Agency says it is possible that no bodies are found in the return of the drift.
The three best options to safely return to Pike River will be scrutinized from next week, before the agency in charge of the restoration recommends the minister whether or not to proceed with re-entry.
Pike River Recovery Agency, CEO Dave Gawn, told Morning report the drift is an entry tunnel of 2.3 kilometers to the mines of the Pike River.
"It goes all the way to a rock wall that separates the mines," he said.
He said the plan is not to enter mine at this stage.
"There is still uncertainty about what actually happened, so the primary goal of restoring the drive is to carry out a forensic investigation of everything that is in it, to try to determine what happened .
"There may be human remains, I will not say that it is unlikely, but it is less likely," he said.
He said that since the explosion the furthest people have gone downhill is about 300 meters.
"That was when they determined where they would place the 170 meter seal, other than that it was investigated by robots, which has not been investigated, is about the last three to four hundred meters of the drift."
He added that the status of the tunnel is unknown, and the weather conditions may be less than ideal, so it is possible that the re-entry would cost more than the originally budgeted $ 23 million.