The council has told residents the mill's owner, Rotorua-based Pedersen Group, has until July 21 to come up with "details of timetabled solutions Lumbercube will undertake within its operations".
To date, the mill's owner has spent more than $2.3 million in attempts to mitigate the noise.
But, on May 3 the Eastside Residents' Action Group asked for a copy of an acoustics report prepared for the council. The request was declined.
The group responded by narrowing the scope of its request to just the data collected, to find out if the mill had broken noise limits set out in the district plan, but the second request was also declined.
According to the council, releasing the information would prejudice its investigation and break legal privilege.
The council's official response said: "Both the collection of the data by council and its subsequent provision to Malcolm Hunt, council's acoustic expert, was undertaken pursuant to the instructions of council's solicitors, Tompkins Wake, in order to assist in council's investigation under the Resource Management Act 1991.
"Making the data available would be likely to prejudice council's investigation under the RMA; and withholding the data is necessary to maintain legal professional privilege."
But, the decision has angered the chairman of the Eastside Residents' Association, an incorporated society born out of the Eastside Residents' Action Group.
Association chairman Ra Daniels questioned why the information could not be released.
"It's important people know this. Without clarity people feel like they are being fobbed off."
He said families were struggling with a lack of sleep, fatigue, stress and general unhappiness.
"It's very unsettling," he said.
"I don't think they are facing up to reality. They keep directing us back to the council, but the people really want to hear from them."
Mr Daniels said the group were not against the mill providing jobs or its economic benefit to the district: "But it's appalling we have had to wait 10 months for action to be put in place and we still don't know if it will resolve the situation." He said the association was working on an action plan for the future. "When a community has to start organising itself like this it tells you something is seriously wrong."
The Rotorua Daily Post approached the council for comment and was referred to information on its website.
That indicated staff were still monitoring the situation and were working closely with Lumbercube, and the mill was still on target to finalise a noise mitigation plan by May 31 and implement it by July 21.
Lumbercube spokesman Brent Devcich declined to answer questions regarding a meeting with the residents' association, instead issuing a short statement: "As you're aware, council has requested that all feedback regarding noise issues be formalised, which is why they've set up a system to receive and document ratepayers' concerns.
"Lumbercube encourages the Eastside Residents Association to voice any concerns through council's agreed process."
