The 17-year-old daughter of missing Chinese rights lawyer Gao Zhisheng has appealed for help from US President Barack Obama, saying Beijing had kidnapped him and that police beat her as a child.
Grace Geng, who now lives in the United States with her mother and brother, urged Obama to ask Chinese President Hu Jintao for information about Gao's whereabouts when the pair meet next month at a Group of 20 summit in Seoul.
"President Obama, as the father of two girls yourself, please ask President Hu to tell this daughter where her father is," Geng wrote in an opinion piece published Thursday in the Wall Street Journal.
"I know my father is just one man. But I also know that if the Chinese government is allowed to blatantly violate its own law with respect to my father, it is only a matter of time before the next father disappears."
Gao -- who defended some of China's most vulnerable people including underground Christians and coal miners -- disappeared in February 2009, sparking global concern.
He only reappeared in March this year when he was apparently released by police, speaking with a few friends and colleagues, many of whom reported that he continued to be tailed by authorities and was in ill-health.
"He wasn't allowed to talk about what happened to him or where he was during that terrifying year. But I was able to tell my father that I love him over the phone," Geng said.
A month later, Gao disappeared again and has not been heard from since.
"Six months ago last week, the Chinese government kidnapped my father, Gao Zhisheng," Geng wrote.
"My father is a lawyer, an increasingly dangerous profession in China."
Geng said police beat her and her mother when Gao's troubles began about five years ago, when he renounced his Communist Party membership and openly called for an end to a crackdown on the banned Falungong spiritual group.
In December 2006, he was convicted of subversion and given a suspended sentence of three years in prison, immediately placed under house arrest and put on probation for five years.
Geng said her father was tortured during his time in detention.
"I knew that when my father came home to serve his suspended sentence, his skin had turned black. I knew that my father couldn't get out of bed in the morning without my mother's help. And I knew that my father was scared," she said.
The teen said police beat her when she was 12 and authorities prevented her from attending school when she was 15, helping to push her mother toward seeking political asylum in the United States. They fled China in early 2009.
Gao's brother Gao Zhiyi, who lives in northern China, told AFP last week that he had come to Beijing to report the lawyer's disappearance and seek information, but was turned away by police without any news.