A group fighting to save Christchurch Cathedral wants the Anglican Church to release all the documents leading up to the decision announced in March to demolish it.
Demolition started this week and the tower has already been taken down.
New information published in the Press shows months of conflict between the Historic Places Trust, the Anglican Church, Christchurch City Council and the Canterbury Earthquake Recovery Authority over the fate of the badly damaged church.
But information on the Anglican Church's own deliberations is missing from the files.
A spokesman for the Restore Christchurch Cathedral Campaign, Mark Belton, says the withholding of any information leads to questions as to why it is being held back.
He says it would be very helpful if all the available information is made public.
Demolition of the badly damaged building started this week and the tower has already come down, along with part of a badly damaged wall.
But the Restore Christchurch Cathedral Campaign says that does not mean the whole structure needs to go.
It says New Zealand and international engineers have come up with a plan which could still be implemented.
The group agrees the tower and the wall needed to come down but says the rest is salvageable.
The campaign says the cost could be as much as $100 million, but that is much less than the costs of a new stadium or convention centre.
It says $45 million of the cost could be shared three ways between the Government, the council and the church, and the remaining money could come from fund-raising efforts.
When the decision was made to demolish the cathedral to the level of the window sills, the Historic Places Trust said its consultants believed that restoration or reconstruction in a strengthened form remained possible. It stands by this view, even though demolition is underway.
But the recovery authority said the building was far too unstable to send people in for strengthening work without putting them in danger.