By John Ruwitch
SHANGHAI (Reuters) - A prominent Chinese labor activist has been missing for more than 24 hours and his wife suspects he was detained by state security agents after trying to help workers involved in China's biggest strike in years organize their case.
Zhang Zhiru was last heard from when he spoke to his wife, Xiao Hongxia, by telephone at around noon on Tuesday. He told her he had been summoned to a meeting with state security agents from the industrial southern city of Dongguan.
Workers at a Yue Yuen Industrial Holdings Ltd shoe factory complex with about 40,000 employees have been on strike since April 14 over social insurance payments.
Labor activists say the strike, in the Dongguan town of Gaobu, is one of China's biggest since market reforms started in the late 1970s.
"When he went out in the morning he said he was meeting Dongguan state security," Xiao said by telephone from Shenzhen, where Zhang lives.
"Yesterday afternoon, and at night when it was very late and he had not come home, a lot of us tried to call him, but couldn't get through."
Zhang's mobile telephone appeared to be off on Wednesday when Reuters tried to call him.
The Ministry of State Security (MSS) is the Chinese equivalent of the KGB in the former Soviet Union, an intelligence-gathering agency that also suppresses dissent and other activities it deems threats to Communist Party rule.
A man surnamed Wang who answered the telephone at the Dongguan branch of the MSS said he had not heard of Zhang's possible detention.
Zhang had been closely following the Yue Yuen strike and was working with other activists and lawyers to try to help the workers organize to press their demands.
Lin Dong, a colleague of Zhang's at the Shenzhen Chunfeng Labour Dispute Service Center, may also have been detained, Xiao said. Calls to the center went unanswered.
Early last week, Zhang tried to travel to Gaobu to meet workers but was detained by police briefly and sent back to Shenzhen, he told Reuters on Friday.
On Monday, however, Zhang and a lawyer involved in labor issues went to Gaobu and met several workers to discuss their options, said Wang Jiangsong, a Beijing-based labor researcher.
"That's why this has happened," said Wang, referring to Zhang's possible detention.
"But there was nothing wrong with what they did, trying to help the workers."
Zhang is no stranger to pressure from the authorities, and Xiao said he had been detained briefly several times in the past.
His labor dispute center has been forced to move twice since mid-March and is facing a third move. He said he believed authorities had put pressure on his landlords to evict him.
The Yue Yuen complex covers 1.4 million square meters (15.1 million square feet) of floor space, according to its website. In addition to Adidas AG, it also makes shoes for Nike Inc, Saucony and other global brands, workers said.
(Editing by Robert Birsel)