The lawyer for hundreds of people seeking compensation for abuse in state care says she will not recommend a new fast-track process to clients until the Government hands over details.
The Ministry of Social Development said it was making fast-track offers to people who have asked for them, and some had already been accepted.
Under the scheme, claims are accepted on face value with some basic fact checking.
Sonja Cooper, whose firm has more than 650 clients seeking compensation, said she asked for details of the new process weeks ago but had not heard back.
She said the ministry had no reason to withhold information if fast-track claims were already going through.
"Apparently payments are already being made to people who are going through the process without legal representation, because that suggests to me that MSC has some process up and running.
"But it certainly hasn't been able to, or chosen not to, tell us so far."
Ms Cooper said she was worried the scheme was working on a first-in first-served basis.