Barry Sherman, the billionaire founder of generic drugmaker Apotex, and his wife, Honey, a prominent philanthropist, were found dead at their Toronto home on Friday. Police said both died from ligature neck compression and described the deaths as suspicious. Homicide detectives were leading the investigation.

Local reports said a real estate agent discovered the couple hanging near their indoor pool. Police sources said there were no signs of forced entry, and police said they were not searching for outstanding suspects. Some news reports cited a police theory of murder-suicide, but the couple’s four children rejected that suggestion, saying it was inconsistent with their parents’ enthusiasm for life and commitment to family and community. Police said they could not yet say whether foul play was involved.

Friends and relatives were struggling to understand the deaths. Days earlier, Honey Sherman had emailed friends about the couple’s annual trip to Florida and had begun making plans to entertain them at their Palm Beach home. The couple had also recently welcomed a grandchild.

Barry Sherman, 75, founded Apotex in 1974 and built it into an international generic drug business. Canadian Business had estimated his wealth at $4.77 billion, ranking him among Canada’s richest people. Friends described him as intensely devoted to his work. Toronto Mayor John Tory praised his investment in the city and the jobs created by Apotex.

Honey Sherman, 70, was remembered as warm, sociable and determined in her charitable work. She served on boards and supported causes in health care, higher education and the Jewish community. Together, the Shermans donated millions to hospitals, universities and community organizations.

Tributes came from political leaders, friends, former employees and neighbours. Flowers accumulated outside the couple’s home as those who knew them mourned their deaths and awaited answers from the investigation.