Rosen said the portly rapper, whose real name was Dwight Arrington Myers, was having difficulty breathing as paramedics rushed him to the hospital.
The performer had just returned from Europe and was battling pneumonia, KTLA news in Los Angeles reported.
Rosen said Heavy D had come home from a shopping trip Tuesday and began laboring for breath as he walked into his condo building.
“He collapsed in an exterior hallway,” Rosen said. “There doesn’t appear to be any foul play. We believe it was medically related.”
The actual cause of death is pending an autopsy.
Born in Jamaica and raised in Mount Vernon, Heavy D rose to stardom in the 1990s as the frontman for Heavy D & the Boys.
Along with band mates G-Whiz, Trouble T. Roy and Eddie F., he made hip-hop history with hit songs like “Now That We Found Love” and “Nuttin But Love.” They also performed the theme song for the 1990s comedy TV series “In Living Color.”
Heavy D last performed in October at the BET Awards.
In recent years, he had ventured into acting, scoring small movie roles, including one in the 1999 film “The Cider House Rules.”
He won a cameo role as a security guard in the just-released film “Tower Heist,” starring Eddie Murphy and Ben Stiller.
“I’m definitely saddened by the loss of Heavy. He was a really good person,” said Damon Williams, vice president of programming for Music Choice, the multi-platform video and music network.
With catchy dance tunes that included R&B riffs, Heavy D was one of the first rappers to cross over to mainstream popularity, Damon Williams" href="http://www.nydailynews.com/topics/Damon+Williams" >Williams said.
“But I don’t think he ever lost his credibility with the hard-core rap audience,” said Williams.
Other friends took to Twitter to express condolences.
“I am deeply saddened by the sudden loss of Heavy D. A longtime friend and a beautiful person,” wrote Russell Simmons.
LL Cool J tweeted, “May GOD embrace the soul of Heavy D and Bless his family. I respected you Heavy and I always will.”