HALIFAX -- A spokesman for the family of a former Canadian soldier who killed his girlfriend and then himself in their Nova Scotia home last week is challenging recent assertions made by a friend regarding the infantryman's service in Afghanistan.

On Sunday, Jason Hill told The Canadian Press that his longtime friend Marc Poulin had told him he was worried about the impact of an anti-malarial drug he was required to take before serving in Afghanistan.

Hill suggested that the drug may have played role in the murder-suicide, saying he was aware of incidents where Poulin experienced rage that was uncharacteristic for the man he had known for years when they both lived in North Bay, Ont.

However, Poulin family spokesman Shane MacDonald, says Hill's statements regarding the tragic case are inaccurate, and he says the Poulin family has asked him to stop commenting on the deaths.

MacDonald, a cousin and close friend of the former infantryman, says Hill knew Poulin when the two were in high school in the 1990s, but MacDonald says there was little contact between them after that period.

In an emailed statement Monday, Hill said he wanted to retract everything he said about Poulin that applied after 1998, which would include any comments made about Poulin's military service.

"Marc's family and myself do not want any statements from me about Marc after 1998, as I was an outside observer and witnessed very few situations," he said in an email. "I am not qualified to diagnose, nor do I recall specific details."

Hill said his previous assertion that the murder-suicide could be linked to an anti-malarial drug was based on communication he had with another veteran.

He did not respond to a request for an interview.

MacDonald says the family believes Poulin's struggle with post-traumatic stress disorder was "the critical factor" behind what happened in Springhill.

Last Friday, the RCMP confirmed the deaths of 42-year-old Poulin and 45-year-old Jennifer Lynne Semenec in Springhill, N.S., were the result of a murder-suicide.

Both were from North Bay, Ont., and had recently moved to the Nova Scotia town, where their bodies were recovered last Tuesday from a small house following a suspicious fire.