Treasury officials are insisting holders of Solid Energy's debt securities sign confidentiality agreements before they are given information about possible debt write-offs.
Radio New Zealand's business editor understands the confidentiality agreements prevent the investors from discussing the debt restructuring, even with their own financial advisers.
Treasury analyst Darian Woods confirmed it was in talks with all Solid Energy's lenders, including bond holders.
Mr Woods said the talks were aimed at reaching a compromise proposal to stabilise the coal company's financial position.
This implies the bond investors are being asked to accept less than they are owed.
Mr Woods said any successful compromise would need the support of a majority of Solid Energy's bond holders.
Radio New Zealand Business asked Mr Woods repeatedly about the confidentiality agreements the bond holders were being asked to sign and why they were being prevented from discussing the issue with their own financial advisers.
But Mr Woods said all he could say was that Treasury officials are in talks with the banks and other interested parties.
Solid Energy's last available annual report shows that at 30 June 2012, it had $70 million of bonds on issue and its interest-bearing debt totalled $295 million.
In March this year, Solid Energy told Parliament's commerce committee its total debt had blown out to $390 million.