However, his agent confirmed to CNN that the star had in fact passed away, while declining to offer any further details.
"Today the world lost an amazing talent," said Tracy Mapes with Imperium 7 Talent Agency.
His son, singer Robin Thicke, also confirmed the news to the Los Angeles Times, saying his father was "the greatest man I ever met" and "always a gentleman".
The 39-year-old also detailed the touching final moments he shared with his father just days earlier.
"The good thing was that he was beloved and he had closure," Thicke told the publication.
"I saw him a few days ago and told him how much I loved and respected him."
The Canadian actor was best-known for his role as psychiatrist Dr. Jason Seaver in the family sitcom Growing Pains, which launched the careers of Kirk Cameron and Leonardo DiCaprio and ran for seven seasons from 1985.
Thicke amassed dozens of film and television credits across his career, even hosting his own talk show along with acting appearances in the likes of Married With Children, The Love Boat and The Bold and the Beautiful.
Behind the scenes, he was also an accomplished producer and composer of TV theme tunes: He wrote the theme songs for Diff'rent Strokes, The Facts of Life and the original theme tune to Wheel of Fortune.
In recent years, Thicke turned his attention to reality television, starring in mockumentary series Unusually Thicke - a 'reality-sitcom hybrid' which featured his real-life family but satirised the usual reality TV format.
Thicke is survived by three sons, Robin, Brennan and Carter, and his third wife, model Tanya Callau, who he wed in 2005.
Robin, 39, has carved a successful career as a pop singer, with one of the best-selling (and controversial) pop hits of the 21st century, 2013's Blurred Lines, to his name.
The son Thicke was playing hockey with when he collapsed, 19-year-old Carter, is an aspiring actor and writer - and frequently shares pictures of his dad with his 14,000 Instagram followers.
Here they are playing hockey together in 2015:
And here they are earlier this year along with Carter's big brother Robin:
Thicke's ex-wife Gloria Loring, with whom he penned many iconic TV theme tunes, expressed her sadness on her public Facebook page, telling her followers that she had seen the father of her two children Robin and Brennan only weeks ago:
Dear Friends,
Thank you for your kindness concerning Alan Thicke's passing. It is a shock. We were all just together for...
Posted by Gloria Loring on Tuesday, 13 December 2016
Former colleagues and other Hollywood stars have started paying tribute to the TV great:
