A murderer considered a psychopath in a Corrections Department report was stuck with the adverse finding after he asked to be assessed for treatment, a High Court judge has heard.

Phillip John Smith is due to be considered for parole for the first time next March, 13 years into his life-imprisonment sentence for murdering the father of a boy he was sexually abusing.

Smith is concerned that the 1999 psychopathy assessment, and other psychological reports, will count against him getting parole.

In the High Court at Wellington yesterday, Justice Forrie Miller reserved his decision on whether he will, in effect, rule that the reports should be disregarded.

Smith, originally from Wairarapa, asked for treatment in 1998 and the following year a psychologist's report was placed on his prison file.

The conclusions were assessed against a psychopathy check-list which placed him on the borderline of being a psychopath. Trainee psychologists did the work and their ability to properly do their work is in dispute.

Smith is now in Hawke's Bay prison with the equivalent of a low-medium rating.

The Crown is defending the use made of the psychological information about Smith. It says he asked to be assessed for treatment and consented to having a copy of the resulting report placed on his file.

Even if Smith did not realise that meant it would be taken into account for his security classification - which the Crown rejects - Corrections officers were authorised to use it anyway, crown lawyer Chris Curran said.

Smith's lawyer, Tony Ellis, said Smith had agreed to a psychologist writing a report. He was not asked, and did not agree to the psychopathy assessment made two months later.

He was not told the psychologist was a student or that the psychopathy test had not been technically validated for use in New Zealand.