Sylvester Stallone tore into 'Rocky' franchise producers over rights: 'The worst unhuman beings I've ever met in the movie industry'

• Sylvester Stallone voiced frustration over not having an ownership stake in the "Rocky" franchise.
• In deleted Instagram posts over the weekend, he called out franchise producers Irwin and David Winkler.

Sylvester Stallone took to Instagram on Saturday and Sunday in since-deleted posts to call out "Rocky" franchise producers Irwin Winkler and his son David Winkler, primarily over his lack of ownership over the franchise.

Stallone called David's new book, "The Arrangement: A Love Story," the "worst book" he's ever read, and called him an "unbearable worthless dreck" and "painfully untalented," according to The Hollywood Reporter. He also called Irwin "remarkably untalented and parasitical."

"If it wasn't for Winkler there would've been at least another three Rocky's, that would've been wonderful," Stallone wrote on Saturday. "Frankly that crew are the worst unhuman beings I've ever met in the movie industry."

Representatives for Stallone and Irwin Winkler did not immediately respond to Insider's request for comment. David Winkler declined to comment.

This isn't the first time Stallone has aired his grievances over his lack of an ownership stake in the "Rocky" franchise, which also includes the "Creed" films.

Stallone made millions off of back-end deals for the original "Rocky" movies in which he received a portion of the box-office revenue, including $2.5 million for the first movie in 1976, which he wrote, coproduced, and starred in.

But in a 2019 interview with Variety, Stallone lamented that he has never received a portion of the merchandising or licensing revenue the studio MGM (which was acquired by Amazon this year) has made from his likeness.

"They had 100 different licenses, and they said this is all going to be put into the pot, which would have meant hundreds of millions of dollars over 45 years," Stallone told Variety in 2019. "I've never seen that pot. I was very angry. I was furious. 'Rocky' is on TV around the world more than any other Oscar-winning film other than 'Godfather.' You have six of them, and now you have 'Creed' and 'Creed II.'"

Stallone had told Variety that he didn't fight harder for a stake at the insistence of his attorney, and he was "so preoccupied with other things I didn't belabor it."

But the issue still stings decades later.

"I really would like [to] have at least a little WHAT's LEFT of my RIGHTS back, before passing it on to ONLY YOUR CHILDREN — I believe That would be a FAIR gesture," Stallone wrote in a now-deleted followup post on Sunday.

"Creed III" is set to be released in theaters in November. Among the producers are the Winklers.