Jim Flaherty's cause of death was a heart attack, according to police.
Emergency services in Ottawa responded to a call from Flaherty's home around 12:30 p.m. Thursday. Police later said he died there as a result of a heart attack. An official cause of death has yet to be released.
Flaherty was 64 years old and is survived by his wife Christine Elliott and their three sons, John, Galen and Quinn.
The family said in a statement that Flaherty passed away "peacefully" and asked for privacy.
Elliott, who is a Progressive Conservative MPP in Ontario, scrummed with reporters Thursday morning in Toronto, suggesting Flaherty's turn for the worse came as a surprise.
The Ottawa Citizen reported that Labour Minister Kellie Leitch, a medical doctor, administered CPR to Flaherty before paramedics arrived at his condo.
Leitch and Flaherty lived in the same building, and she credited the former finance minister for encouraging her to enter politics. She was visibly upset during Prime Minister Stephen Harper's press conference about Flaherty's death.
— Stephen Maher (@stphnmaher) April 10, 2014
Flaherty resigned as finance minister in March. He had been suffering from a rare skin condition called bulluous pemphigoid and was treating it with a steroid called prednisone. The drug, which is an immunosuppressant, can cause bloating and weight gain, which may explain Flaherty's dramatic change in appearance over the last year.
Because it suppresses the immune system, prednisone often leaves patient susceptible to infection, but the drug has many known side effects, from fatigue to anxiety.
It remains unclear whether there is any connection between the apparent heart attack and Flaherty's condition.