Some current and former officials have said the 2019 F.B.I. analysis sowed doubt within the C.I.A. and parts of the Trump administration about the root causes of the ailments.

Founded in China in the early 1990s, Falun Gong unsettled Chinese government officials and quickly became subject to brutal repression. It has prospered nonetheless.

The dance group has discouraged performers from seeking medical care when they were injured and has subjected them to emotional abuse and manipulation, The Times found.

As the popular dance show grew into an international juggernaut, some of the group’s young performers paid a steep price.