As the entertainment world and her legions of fans mourn the death of Betty White, a representative for the beloved Emmy winner revealed the cause of her death.

White's close friend and agent Jeff Witjas told ABC News, "My understanding is it was natural causes. She died in her sleep, in her own bed. It's as simple as that."

"Betty didn't have illnesses. She didn't have anything. People are putting it out there that she had the booster on Dec. 28 and that she had [side] effects. She never had a booster," he added. "They're politicizing her death, and they shouldn't do that, because she wasn't that type of person in life."

Witjas told ABC News that he visited White in her home about a month before she died and found her to be "all there," albeit physically frail. "We were laughing, her sense of humor was there," he said.

Tributes continue to mount for the late "Golden Girls" and "Mary Tyler Moore Show" actress, who would have turned 100 on Jan. 17. Actress Yvette Nicole Brown recently posted to Instagram footage of herself and her "Community" castmates belting out Toto's "Africa" with White in 2010.

Brown commented that the clip was a video from her old cellphone that she kept private until now.

"I needed a bit of Betty this early morning, so I searched an old computer to find it," she explained. "After seeing it, I figured you guys might need it too."