A man who raped his biological mother after he tracked her down has failed to overturn his conviction.
The 29-year-old man, who was adopted as a baby, was sentenced to five years and nine months prison after being convicted of assaulting and raping his biological mother.
The offence occurred some months after he tracked her down to ask questions about his parentage last year.
Rather than multiple rapes, he was convicted of nine counts of incest after the jury found the sexual relationship they embarked on was consensual to begin with.
The man, who has name suppression, was found guilty of one representative count of rape later in their relationship.
The man's defence appealed his conviction on the "inconsistency" of him being found guilty on a non-specified representative count but not guilty on each of the specified ones.
The Court of Appeal rejected the argument and said it was open to the jury to accept that there was "an escalating pattern of violence" in their relationship.
"(The complainant) said she had to ask permission from the appellant to do everything from eating, showering or even going to the toilet against the threat that she would be punched in the face," the decision reads.
"We consider it was open for the jury to accept her evidence that non-consensual activity had taken place during the period."
The appeal was dismissed.
The man made contact with his biological mother on Mother's Day 2010, moved in with her a few weeks later, and soon began a relationship with the woman, who was separated from her husband at the time.
The man's trial in Auckland District Court in May was harrowing.
Jurors were shown evidence, and the woman broke down repeatedly giving her testimony, and at times ran from the court.
She said she was ''doing what she was told to do'', which included ''performing like a porn star''.
Adopted family squared off against biological family, with the man's adoptive mother telling the court the woman had told her the relationship was consensual.
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