June 4 student leader Chai Ling says her faith is driving her to seek confession of alleged rape by fellow dissident Yuan Zhiming in 1990

Of all the 1989 student leaders who fled China in the wake of the Tiananmen Square crackdown, few have been surrounded by more controversy than Chai Ling.

As the fiery "commander-in-chief" of the student protesters, Chai was accused of recklessness in resisting pleas from the movement's intellectual wing to abandon the scene to avert bloodshed. After fleeing China in 1990 with then-husband Feng Congde, Chai was listed as No4 on Beijing's most-wanted list.

Now, she is back in the spotlight, with stunning accusations that fellow June 4 dissident Yuan Zhiming raped her in 1990 in her flat in New Jersey when the pair were studying at Princeton University. She has been relentless in her pursuit of an admission of guilt from Yuan - a prominent leader of the Chinese Christian diaspora via his US-based China Soul foundation - since she privately approached him about the incident in 2011.

"After I fled China, losing family, country, everything … my body, soul and mind shattered … I never thought that I would be raped by you. What Satan did not accomplish in the fall [of 1989], you did in 1990," Chai said she wrote to Yuan in June last year, in an exchange she made public.

Yuan on Monday denied raping Chai, but admitted "extramarital sexual iniquity" with her. He said the act was consensual and that the pair continued a romantic relationship afterwards, a claim that outraged Chai . Neither Chai nor Yuan responded to requests for an interview.

The claims against Yuan exploded into the public arena in November when Chai penned an open letter and named her alleged attacker. Despite weeks of denials - and China Soul's threats of legal action against Chai's supporters - Yuan last weekend quit all his religious duties, begged forgiveness from his followers, apologised to Chai and said he would "retreat in the Lord and seek renewal". He continues to deny raping her.