The Canadian billionaire couple found dead at their home in Toronto last month were murdered in a targeted killing, police say.

The bodies of Barry, 75, and Honey Sherman, 70, were found on 15 December.

Police said on Friday no-one had been charged, and declined to comment on any suspects.

Barry Sherman, one of Canada’s richest men, and his wife were well-known for their philanthropy, and their sudden deaths stunned many in the country.

Media reports in the days after the couple’s bodies were discovered quoted police sources saying they were investigating a murder-suicide theory.

“I don’t know where that came from,” Toronto police detective Susan Gomes told reporters, adding that it was just one of several theories under consideration.

The new details of the case came on the same day that the pharmaceutical giant Apotex that Barry Sherman founded announced its CEO’s resignation.

What was revealed on Friday?

Detective Gomes said the couple were last seen alive on the evening of 13 December and had no communication with family after that point.

She said police investigators had found no sign of forced entry on any access points to the home.

Two days later the pair were found fully clothed by the pool “hanging by belts in a semi-seated position on the pool deck,” she added.

Ms Gomes said that police came to the conclusion they were dealing with a double homicide after “six weeks of evidence and its review”. Police believe the couple were “targeted”, she added.

“I’m not going to discuss the suspects, or any suspects,” Ms Gomes said. “I’m not going to discuss any motives.”

She said there was a “significant list of people” they were speaking to in the ongoing investigation.

Police have until now released few details in the case, confirming only that they both died from ligature neck compression, or strangulation with material.

Who were the Shermans?

A gifted student, Barry Sherman entered the pharmaceutical trade through his uncle's Empire Laboratories, working for him while still at university before buying the company when his uncle died.

He went on to sell Empire, creating Apotex, the company that made him a billionaire and which now employs more than 10,000 people.

But he became embroiled in a family dispute, with his uncle's children seeking a stake in Apotex, arguing they had been cheated. A judge threw out their claim earlier this year.

He also faced an investigation as to whether he had improperly held a fundraiser for Justin Trudeau before he became prime minister.

Mrs Sherman was a board member for several hospitals, charities and Jewish organisations. The couple had four children and have given millions to charity.

The couple’s public funeral took place on 21 December and was attended by many from Toronto’s prominent social circles, as well as dignitaries like Canadian Prime Minister Justin Trudeau.

•Excerpted from a BBC report.

Update news