A Pakistani government minister is facing charges of wrongful confinement after a Canadian businesswoman staying at his home in Islamabad died under suspicious circumstances.

Kafila Siddiqui, a former Toronto-area resident, had been staying in the capital city at the home of the Minister of State for Communications Muhammad Shahid Jamil Qureshi.

"We have registered a case against the minister this afternoon, on charges of wrongful confinement," police Senior Superintendent Zafar Iqbal told The Globe and Mail in an interview Monday.

Siddiqui's brother, Mustafa Qayyum, is named as the complainant in the case. He alleges that Qureshi held his 40-year-old sister against her will for three months.

Siddiqui, who was buried on Sunday in Karachi, was declared dead shortly after Qureshi brought her to a hospital Saturday.

In an interview with The Globe, the minister said he was not in business with the 40-year-old.

However, Canadian corporate records obtained by the newspaper show that a person with the same name is listed as a co-director, along with Siddiqui, of two Ontario-based companies.

Qureshi also denied that the pair were romantically involved.

"She was very religious," he said, "and, in fact, during the last few months she was in such a deep depression that she had stopped eating and drinking, and only consumed dates and ab-e-zamzam (holy water)."

Qureshi told The Globe that he has been wrongly accused and instead blamed Siddiqui's death on her financial stress and depression.

He said Siddiqui returned from a trip to Canada last February and was depressed because "she said that her husband had verbally divorced her."

Qureshi said he met Siddiqui at a business conference in Toronto in 2005 and that she had been renting the ground-floor section of his home prior to her death.

Investigators found vomit in the room where Siddiqui had been prior to her death but an initial postmortem has proved inconclusive.