Mystery focuses on whether billionaire killed his wife

Police cars are parked outside the home of billionaire Barry Sherman and his wife Honey in Toronto. Photo / AP

Police in Canada are investigating whether one of Canada's richest men murdered his wife before killing himself, according to reports.

Barry Sherman, 75, the founder of pharmaceutical giant Apotex, and his wife, Honey, were discovered hanging side-by-side near the indoor swimming pool at their home in Toronto.

Canada's Globe and Mail and Toronto Sun newspapers reported that police were investigating whether Sherman killed his wife and hanged her body before killing himself. "Forensics need to be done and post-mortems on the bodies, but at this stage it appears there was no forced entry and no evidence of anybody else in the house," a police source told the Toronto Sun.

The couple's US$5.4 million ($7.6 million) six-bedroom home had been put up for sale 18 days ago and an estate agent discovered the couple.

The National Post reported that Sherman, who drove a "beat-up old car" and did not fly business class, failed to show up for work last Friday, "an unusual occurrence for the work-obsessed man", according to friends.

Sherman, with a fortune estimated at US$3.2 billion, was a prominent donor to Justin Trudeau's ruling Liberal Party. During Canada's 2015 national election campaign, he held a fundraiser at the couple's home, where guests included Trudeau. The event later became the subject of a probe by Canada's lobbying commissioner as to whether Sherman breached rules against fundraising and lobbying. Earlier this year, Apotex sought a judicial review in a bid to quash the investigation, which the company called an "unanchored fishing expedition".

Sherman was also involved in a series of lawsuits, including a decade-long battle with cousins seeking compensation over allegations he cut them out of the company that made him rich.

A judge dismissed that lawsuit in September, but the cousins reportedly planned to appeal the ruling.

Sherman began his career in the pharmaceutical industry in 1967, when he bought Empire Laboratories, a company established by Louis Winter, his uncle.

In 1974, Sherman founded Apotex, now the world's seventh-largest drugmaker that exports more than 300 generic drugs to more than 115 countries. He stepped down as chief executive in 2012, but stayed on as chairman.

Sherman and his wife, who have four children, were also known for their philanthropy. He donated tens of millions of dollars to the United Jewish Appeal, and Honey Sherman was a board member of the Simon Wiesenthal Centre.