The nephew of Sylvester Stallone posted Facebook messages suggesting that the "Rocky" actor was partly to blame for his son Sage's mysterious death.

The messages claimed that Stallone failed to return his son's call to wish him happy birthday on July 6.

The comments, written by the cousin, Edd Filiti were obtained by Celebuzz and has since been removed.

"What did he do wrong, say happy birthday," Filiti, Sage's cousin and the son of Stallone's half-sister Toni Ann, wrote on Facebook.

"Neither you [Stallone's wife Jennifer Flavin] or he could return a phone call, which is all he wanted, his father. I know you don't care what happened, but you'll care when your (sic) squirming under the burning magnifying glass of public opinion."

He also added: "You people make me f*ckin sick." 

Filiti did not return a request for comment.

According to another Celebuzz report, Sage was "depressed" before his death because he was estranged from his father, according to a family insider.

"Sage was not allowed in his father's home and he admitted to other family members of his devastation that he'd seemingly been cut out of his father's life," the family friend revealed.

"Sage idolized his father but they had become estranged in recent time. It crushed him."

Sage, 36, was found in his Hollywood Hills home Friday by a housekeeper, reportedly surrounded by bottles of prescription pills and empty cans, according to The Daily News.

Police officials did not specify what type of pills were found, and whether or not they played a part in Sage's death, though they said the death was likely an accident since no suicide note was found, and foul play was not suspected.

An autopsy and a toxicology test were completed Sunday, but the results of the latter will not be released for several days, if not weeks.

Sage's mother, Sasha Czack, split with Stallone in 1985 after 11 years of marriage. Stallone's wife Jennifer Flavin married Stallone in 1997.

On Sunday night, the elder Stallone issued a statement following Sage's death.

"When a parent loses a child there is no greater pain... This agonizing loss will be felt for the rest of our lives," Stallone told TMZ in a statement. "Sage was our first child and the center of our universe and I am humbly begging for all to have my son's memory and soul left in peace."

Stallone will appear in "The Expendables 2," the sequel to his 2010 hit "The Expendables:. The film will be in theaters nationwide as of August 17.

Stallone wrote, directed and stars in the movie with co-stars Jason Statham, Jet Li, Dolph Lundgren, Terry Crews, Mickey Rourke, Randy Couture, Eric Roberts, Stone Cold Steve Austin,  Bruce Willis and Arnold Schwarzenegger.