Wellington, Feb 25 NZPA - The Supreme Court has reserved its decision on an appeal by the Solicitor General over the acquittal of George Gwaze for the murder of his 10-year-old niece.

Solicitor-General David Collins, QC, told the court today the acquittal was a miscarriage of justice and a retrial should be held.

Gwaze was found not guilty of the murder and sexual violation of Charlene Makaza following a High Court trial at Christchurch in May 2008.

The Crown unsuccessfully appealed the verdicts in the Court of Appeal, but the Supreme Court agreed to hear today's appeal.

Charlene, who lived with her extended family in Christchurch after being orphaned in Zimbabwe, was found unresponsive in her bed on January 6, 2007, and later died.

The Crown claimed Gwaze suffocated his niece after sexually assaulting her in her bed.

Medical evidence was given that damage to Charlene's genital and rectal areas indicated sexual assault, but defence lawyers said the death was from an HIV-related infection.

Dr Collins told the Supreme Court today that hearsay evidence given by a South African doctor should not have been admissible at the trial.

Paediatric surgeon Heinz Rode, who was called by the defence late in the trial, had testified in a statement that Charlene's symptoms were similar to those of South African Aids victims.

However, he later expressed alarm that his statement was to be used in court, Dr Collins said.

There were inconsistencies in the terminology Dr Rode had used, with one statement referring to HIV infection, while a later statement referred to "full-blown Aids", Dr Collins said.

Dr Rode's statements should not have been admissible as evidence, nor should they have been given as much weight as they were in the judge's summary of evidence.

Allowing the evidence had forced a miscarriage of justice and a retrial should be held, Dr Collins said.

Counsel for Gwaze, Jonathan Eaton, said the defence case had rested on circumstances at the time of Charlene's alleged rape, and not Dr Rode's hearsay evidence.

Nonetheless, it was "unfair" to say the trial judge had been wrong in his assessment of the evidence, he said.

"The trial judge did not make an error in admitting that hearsay."

He agreed the evidence was intended to undermine the Crown's medical witnesses.

"It was testing what they do or don't know."

The differences in terminology between Dr Rode's statements did not point to inconsistencies, and nobody had raised that point at the trial, Mr Eaton said.