Pike River Recovery Agency is on track to deliver plans to enter the coal mine to recover remains of the 29 men who died in 2010.
The agency was set up as part of the new government's election promise to try for a manned re-entry of the 2.3 km long entry tunnel to the West Coast coal mine.
The aim would be to find remains of the miners and contractors who died in the explosion in 2010 and to search for clues as to why it exploded.
A group of experts has spent the past few months coming up with a plan for how this could be done safely.
This will be presented to the Pike River re-entry minister Andrew Little by Wednesday for a final decision.
The head of the agency, Dave Gawn, described the report as extensive.
"We're still on track at this stage to have the agency's preferred option to the minister by 31 October, but then he will take some time, I think, to work through the amount of technical stuff that is involved in that before he makes his decision", he said.
The plant that would pump nitrogen in to the mine to help remove potentially explosive methane is due to be switched on in about two weeks.
Mr Gawn said they planned to secure key pieces of equipment, such as the nitrogen plant, before a final decision on re-entry was made. This would speed up the process.