TORONTO -- Ontario's highest court upheld the second-degree murder conviction of an Afghan immigrant who nearly decapitated his wife, calling the woman's death a "horrific" killing in a decision released Wednesday.

Peer Mohammad Khairi, a father of six, had argued that the judge who presided over his trial made several errors, and asked the appeal court for a new trial.

If a fresh trial couldn't be ordered, Khairi had asked that his period of parole ineligibility -- currently set at 15 years after he was sentenced to life in prison -- be lowered to 10 or 11 years.

He was turned down by Ontario's Court of Appeal on both fronts.

"The conviction appeal is dismissed. While we grant leave to appeal the sentence, the sentence appeal is dismissed," the court's decision said.

Khairi had admitted to killing his wife in March 2008, it was the circumstances of the death that had been in dispute at his trial, the court noted.

"He contended that he lacked the intent for murder due to mental health issues. Alternatively, he claimed that he stabbed his wife in the heat of passion, caused by her allegedly provocative words and conduct," the appeal court wrote.

A jury deliberated for three days in 2012 before finding Khairi guilty of second-degree murder.

In his appeal, Khairi argued that the trial judge erred by not declaring a mistrial after what was allegedly an "improper" opening statement from Crown prosecutors, whose effect was allegedly to prevent him from receiving a fair trial. He also claimed the prosecution's closing address was inflammatory.

The appeal court agreed that the Crown's opening statement was improper, but found that the trial judge adequately instructed the jury that the Crown's remarks exceeded the scope of a proper opening statement.

"Any prejudice that might have been caused by the opening was properly addressed through the trial judge's instruction," the appeal court said. "Nor do we give weight to the submission that the Crown closing was improper or required a jury instruction."

Khairi had also argued that the trial judge made errors in instructions to the jury on the evidence of a psychiatrist, the issue of the statutory defence of provocation and the jury's ability to accept "some, none or all" of Khairi's evidence.

The appeal court disagreed, finding that the trial judge "painted a fair picture" of the psychiatrist's evidence and delivered adequate instructions to the jury.

While it did find that during the sentencing phase the trial judge erred in stating that the jury's verdict was a rejection of Khairi's evidence concerning his wife's provocative words and actions, it found the error did not have a material effect on Khairi's sentence.

Khairi, who was born in Afghanistan, immigrated to Canada with his wife and children in 2003 after having spent the previous 15 years in India.

The family settled in Toronto but due to the couple's limited education and inability to speak English, neither of them could find work, court documents have noted.

In 2006, the family had financial troubles and the relationship between Khairi and his wife became strained, the documents said.

"There was evidence that the appellant was abusive and that his wife had told him that she was going to leave him and take the children with her," the decision said.

The sequence of events leading up to the death of Khairi's wife has remained a point of contention, but the appeal court noted the gory nature of her demise.

"The circumstances of the killing were horrific," it said.