An international team of mine safety experts says the bodies of the 29 Pike River miners can be recovered.
A proposal to enter the collapsed mine and recover the victims has been presented today to new West Coast mine owners Solid Energy, Mines Rescue and the Government.
The detailed plans outline exactly how to go underground and safely reach the men, which the grieving families have been fighting for since the November 2010 tragedy.
"My experts are very confident," said Bernie Monk, spokesman for most of the 29 families, whose son Michael died in the tragedy.
"The plans include how to get down the drift, how to get the miners out of the mine, and all of the costings."
Dave Feickert, a New Zealand mining consultant, along with former UK principal mines inspector Bob Stevenson, and Dr David Creedy, a fellow Englishman and methane gas specialist, arrived on the West Coast on Monday - just hours after a scathing Royal Commission of Inquiry report into the disaster was released.
Dr Creedy said the report "read like a horror story" and they were shocked by its findings, which made 16 recommendations to improve mining health and safety.
On Monday, the independent team vowed that by the time they left Greymouth this weekend, they would be able to tell the families conclusively if a recovery operation was safe and feasible.
They have spent the week meeting the new mine owners, Solid Energy, as well as Mines Rescue officials, Ministry of Business, Innovation and Employment officials and locals.
They have pored over the Royal Commission report, visited the Pike River mine, and ventured 170m underground, while even flying over the mine in a helicopter to better understand its geography.
Now, they think they have found a way in to recover the trapped men.
"We've worked extremely hard this week and I've been very impressed with their work," Mr Monk said.
He confirmed the plans were sent to the Government, Mines Rescue and Solid Energy today.
Solid Energy said today it had worked with the experts all week, providing them with information and mine access.
"We're looking forward to seeing what they come up with," a spokesman said.
Mr Monk accepted the plans were only a starting point and was not allowing himself to get too hopeful because he'd been "kicked in the guts every time".
"There will be questions over what is proposed but the experts are prepared to front up and answer them."
Mr Monk said he would push Prime Minister John Key to fund a recovery operation if a feasible plan was possible.
"What we've always wanted is to bring our loved ones back home."
Mr Stevenson said on Monday that going back into the mine was a "serious situation", with high volumes of potentially explosive methane gas in the mine.
"This is not a decision we'll take lightly," he said.
He said re-entry to mines has been done in the UK many times but none of them were operating under such "appalling" standards as Pike River.