What happened to Fan Bingbing, China’s most famous actress?

Ms. Fan, who turns 37 on Sunday, has dropped out of public view for more than three months — the victim of a sudden and precipitous fall from grace.

Her disappearance has been greeted with concern among fans and fear among her counterparts in the industry. It has fueled a flurry of rumors of personal rivalries and political intrigue, even at the pinnacles of power in Beijing, though few concrete facts.

That so little is known about someone so famous in China — even whether she is in detention, or in hiding — says much about the murky intersection of politics and business, entertainment and celebrity.

“She’s like collateral damage,” Hung Huang, a critic and publisher, said.