OTTAWA -- The Supreme Court of Canada has restored the second-degree murder conviction of a Halifax-area man who admitted to burning his girlfriend's body but insisted he didn't kill her.

Paul Trevor Calnen was convicted by a jury of second-degree murder in the death of Reita Louise Jordan, 35, in March 2013.

The man from Hammonds Plains, N.S., pleaded guilty to burning her body and scattering her ashes in a lake, but maintained he did not cause her death, claiming she accidentally fell down the stairs.

The Nova Scotia Court of Appeal overturned the murder conviction in 2017, in part because the lower court judge did not properly instruct the jury.

The appeal court said the trial judge erred in denying a motion from Calnen to remove second-degree murder as an option for the jury, and replace it with manslaughter.

In a divided decision released Friday, the Supreme Court concluded that evidence of Calnen's conduct after Jordan's death was admissible in determining whether he caused her death and whether he intended to kill her -- two essential elements of second-degree murder.

The court also concluded the trial judge's instructions to the jury were adequate, and the fact he did not instruct them about general propensity reasoning -- concluding someone has committed an offence based on evidence of the accused's bad character -- did not amount to a "reversible error."

"The risk that the jury would engage in general propensity reasoning based on the evidence of the accused's after-the-fact conduct was considerably offset by the trial judge's introductory and final jury instructions, which were neutral, fair and balanced," the 137-page judgement said.

"The trial judge's opening instructions and his answer to a question from the jury insulated the jury from reasoning that the accused's guilty plea to indecent interference with the victim's remains meant it was more likely that he committed second-degree murder."

The decision went on to say: "It is clear that he properly equipped the jury to make reasonable inferences from the circumstantial evidence without resorting to specious reasoning or speculation."

Calnen's lawyer, Peter Planetta, did not immediately return a request for comment Friday.

The Nova Scotia Appeal Court decision said Jordan was living with Calnen at the time of her death.

The sexual relationship, which appeared to have been fuelled by their joint use of crack cocaine, was coming to an end.

Text messages revealed Jordan was planning to move out of Calnen's home, and that there was a heated exchange between the two.

Calnen claimed that Jordan took a swing at him in anger, missed, and fell down the stairs.

He said he tried mouth-to-mouth resuscitation, but decided she was dead.

Rather than call for help, Calnen consumed crack cocaine and decided to remove Jordan's body from his home.

Over the following weeks, Calnen went to great lengths to destroy her body, burning it a number of times before scattering her ashes in a lake.

Calnen was sentenced to life in prison with no chance of parole for 15 years. He received a concurrent sentence of five years after pleading guilty to indecently interfering with human remains.

-- By Aly Thomson in Halifax.