Image copyright Reuters Image caption Jonathan Sherman gave a moving eulogy at the memorial service of his parents

Shattered by grief, honest, emotional, and still grappling with the mystery of the tragedy, Barry and Honey Sherman's family gathered to say their goodbyes.

Thousands of mourners - friends, dignitaries, employees - attended Thursday's memorial service to pay tribute to the couple's life and legacy.

The bodies of the Canadian billionaire, 75, and his wife, 70, were found in their Toronto home last Friday.

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

Police are treating the deaths as suspicious.

"This has been so incredibly painful and bizarrely surreal," said their son Jonathon Sherman, who added that the family was angered by how little information they have received about their parents' death from authorities.

Image copyright Reuters Image caption Honey and Barry Sherman were renowned for their charity fundraising

"We've had to navigate through a terrifying maze of non-information and unfounded speculation while trying to support each other emotionally," he told the crowd.

He went to eulogise both his parents in an emotional tribute, calling his mother "the eternal party animal who wouldn't let anything get in the way of a good time".

She was "the magnet and glue that pulled us together and made us stick", he said.

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

Jonathon Sherman recalled his father as a man with a gentle sense of honour who was stickler for grammar, and who made time to spend with his family despite the demands of running the company that made him one of Canada's richest men.

"You were a real life superhero," he said at the service, which was in a massive conference hall west of Toronto.

Mr Sherman was the founder of pharmaceutical giant Apotex, which sells generic medicines around the world, and the couple were prominent philanthropists.

Apotex now employs some 11,000 people.

Image copyright Reuters Image caption Thousands attended the funeral for the Shermans in a convention centre outside Toronto

Many of the employees who attended wore blue articles of clothing, the company's colour.

Friends said the couple were generous, modest, casual, and down to earth.

Joel Ulster, a friend of Barry Sherman since they were 16 years old, said his friend was an aggressive businessman with a big heart.

"With Barry it was no bullshit, pretty much all of the time," he said.

Newspaper magnate Paul Godfrey said their loss leaves a great vacuum in Toronto society.

"It's just an awful feeling to have, to know they will no longer be there," he said before the service began.

'Enthusiasm for life'

But questions around the couple's death was not far from the thoughts of those attending the memorial.

"We have to wait to find out what happened here - that's the sad part," said Mr Godfrey.

He said the homicide detectives on the case were "the best in the business, so hopefully we'll get an answer to what really happened".

Shimon Fogel, who knew them both through his work with the Centre for Israel and Jewish Affairs, told journalists that "it's just too difficult to contemplate what the particular circumstances may have been" regarding the couple's death.

Image copyright Reuters Image caption Canadian Prime Minister Justin Trudeau attended the service

Over the weekend, police sources told several Canadian media outlets that an early theory in the investigation was that Mr Sherman had killed his wife before killing himself.

The family said in a statement that no-one close to the couple believed this.

"Our parents shared an enthusiasm for life and commitment to their family and community, totally inconsistent with the rumours regrettably circulated in the media as to the circumstances surrounding their deaths," it read.

The statement went on to call for a "thorough, intensive and objective criminal investigation", and for the media to stop reporting on the cause of the deaths until the investigation was finished.