The comment in question -- "According to the karma of past actions, one’s destiny unfolds, even though everyone wants to be so lucky ... Nothing stays in the dark 4ever!" -- came from a fake, unverified Twitter account that the rep said has since been taken down.
Bonet "continues to have no comment on the subject" of sexual-assault allegations being made against the 77-year-old comedian, the rep said.
Bonet played second-oldest child Denise Huxtable on "The Cosby Show" and its spinoff, "A Different World." She hit the small screen most recently in an episode of "New Girl," playing a new-agey "education guru" leading Zooey Deschanel and Damon Wayans Jr. through a teachers conference.
Last week, "Cosby" cohort Raven-Symone similarly denied having anything to say about the ongoing controversy after a website published a fake story claiming she was accusing her onetime onscreen elder of abusing her in the years after the show wrapped.
For the record
3:51 p.m., Nov. 25: A previous version of this post referred to Bill Cosby's character on "The Cosby Show" as Raven-Symone's character's former onscreen dad. On the show, Cliff Huxtable was Olivia Kendall's step-grandfather.
"I was NOT [taken] advantage of by Mr. Cosby when I was on the Cosby Show! I was practically a baby on that show and this is truly a disgusting rumor that I want no part of!" the 28-year-old wrote Wednesday on Instagram. "Everyone on that show treated me with nothing but kindness. Now keep me out of this!"
That Instagram account is linked to Raven-Symone's verified Twitter account.