Chilling twist after billionaire couple found dead in their mansion

The devastated children of a Canadian pharmaceutical tycoon who was found dead alongside their mother have hired private investigators to prove they were murdered and not killed in a murder-suicide.

Barry Sherman and his 70-year-old wife Honey, who have an estimated fortune worth more than $3 billion, were found dead in their Toronto home on December 15.

Toronto's homicide unit, which took over the investigation into the "suspicious" deaths, earlier said that they had been strangled to death, but stopped short of calling them homicides.

Local media reported that police were operating under the theory that the 75-year-old chairman of Apotex may have killed his wife and then taken his own life, given how their bodies were found.

Barry Sherman and his 70-year-old wife Honey were found dead in the basement of their Toronto home. Source: CBC Toronto

The pair were found murdered inside their mansion on December 15. Source: Getty

However, the Sherman's four children are disputing that line of theory, saying that a murder-suicide makes no sense.

They hired criminal lawyer Brian Greenspan, who in turn hired private detectives and asked for a second autopsy before their funerals were scheduled to go ahead.

'Contract killing'

The pathologist and the detectives, which included former Toronto homicide investigators, found markings on the victims' wrists indicating that their hands had been tied with cord or a plastic zip tie.

When the bodies were found the wrists were untied, and no rope or cords were found, the Toronto Star reported.

Furthermore, toxicology tests on the bodies showed no abnormal sign of drug use.

The team concluded that the couple was strangled to death with men's leather belts found around their necks attached to a bar at the edge of the pool.

Private investigators now say the billionaire couple were murdered in what was set up to look like murder-suicide. Source: CBC Toronto

Barry Sherman founded Apotex in 1974, a company that has gone onto become Canada's largest maker of generic drugs. Source: AFP

Sources close to the family probe used words like "professional," "contract killing," and "staged homicide" to describe the couple's death, the Star said.

The private detectives have not been granted access to the house, according to the Star, which quoted sources as saying that there was no damage or other evidence inside pointing to a home invasion.

And though both the police and private detectives canvassed nearby home for surveillance video, "nothing has come from a study" of the footage.

Sherman Funeral Family and VIP leave after paying their respects to Honey and Barry Sherman at International Center in Toronto. Source: Getty

The investigation into their death continues. Source: Getty

In the days after their death long-time family friend Fred Waks, who regularly socialised, dined and travelled with the Shermans, shut down any claims of a murder-suicide.

"I think it's impossible," he told CBC.

"I don't believe [it] for a second, I think it's impossible... none of us believe it."

Sherman founded Apotex in 1974, and over the following decades became known as a ruthless businessman who shunned the limelight while revolutionizing the drug industry in Canada.

Today, the company employs over 11,000 people and sells 300 generic drugs in 120 countries.

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