Royal commissioners have rejected a legal bid to suppress key Department of Labour evidence at the inquiry into the Pike River disaster.

Lawyers acting for Pike River Coal Ltd, its former chief executive Peter Whittall, other company executives and Valley Longwall International Pty Ltd applied to keep a DOL investigation titled "Pike River Mine Tragedy 19 November, 2010" secret.

The investigation forms part of the evidence for 25 health and safety charges levelled against the applicants last month.

They argued the investigation should be restricted to the commission and parties with a "legitimate interest" in receiving it.

That request was turned down by the Royal Commission of Inquiry on the grounds it contained useful information.

The inquiry hearings were of public interest and should be reported accurately, its ruling said.

It said that "A further concern is that the suppression orders sought, if granted, would have the potential to distort a proper understanding of the evidence."

However, the commission said the DOL investigation would not be widely available. It would only be released to those who applied for it in writing.

A Royal Commission of Inquiry spokeswoman said the evidence was part of an investigation leading up to charges being laid, and was therefore different to other evidence received by the commission.

"The Commission needed to strike a balance between the use of the report for its purposes and the sensitivity around it as part of the DOL and criminal investigations."

(Sourced from www.nzherald.co.nz)