BEIJING -- A brief news article published on Sunday by a score of state-run news media outlets offered an account of an unexpected judicial verdict: a Beijing municipal court had sentenced 10 people to jail for illegally detaining and assaulting a group of citizens who had come to the capital to lodge complaints about official malfeasance in their hometown in China's central Henan Province.
The defendants had flashed government identification cards when they rounded up the 12 petitioners and bundled them off to a secret "black jail" on the outskirts of the capital, according to The Beijing Youth Daily, the first paper to publish the news.
Legal rights advocates hailed the landmark court decision, said to be the first of its kind in any such case in the capital, as did many users of Sina Weibo, the Chinese equivalent of Twitter. "Great news," wrote one. "This is the start of rule of law."
But apparently the news was too politically discomfiting to survive. By the end of the day, the article had been deleted from most Web sites, and a court employee insisted that news accounts of the verdict were false. The Beijing Youth Daily, the court employee said, had agreed to publish an apology.
No apology had appeared on the newspaper's Web site by late Sunday.
At first glance, the episode appeared to highlight imperfections in the Communist Party's well-oiled propaganda machine: if the news was indeed untrue, why did tightly controlled media outlets, including People's Daily and the Xinhua news agency, publish it? (The censors were not terribly effective: as of early Monday, a handful of Chinese Web sites and news portals still featured the news.)
But it also underscored official ambivalence over an extralegal form of detention that has drawn criticism from rights activists and outraged many Chinese. In recent years, top officials have repeatedly denied the existence of black jails, which are financed by local governments desperate to prevent aggrieved citizens from filing complaints against abusive police officers or corrupt local leaders in China's hinterland.
Even if the vast majority of petitions are unsuccessful -- one study suggested fewer than 1 percent received an official response -- local Communist Party bureaucrats have come to believe that the complaints, if successfully lodged in Beijing, can harm their career prospects.
To stop people from reaching the capital's main petition office, the State Bureau for Letters and Visits, municipal and provincial governments pay "retrievers" to grab petitioners off the street and bundle them off to cheap hotel rooms or rented basements. Some are held for weeks under dismal conditions until officials can send them back to their hometowns. Stories of beatings, rape and sometimes even death in custody are legion.
Official denials of the existence of black jails were challenged in 2010 after two Chinese publications ran exposés about a Beijing security company that was paid millions of dollars by local governments to capture and expel petitioners from the capital. Although the articles were later removed from the publications' Web sites, the Beijing police reportedly detained two of the company's executives and promised an investigation.
Last year, China Daily and The Beijing News wrote about a black jail where dozens of people spent months packed into three small rooms.
Legal experts say the ad hoc detention system continues to flourish. According to the account published on Sunday by The Beijing Youth Daily, the Chaoyang District Court in late November convicted 10 men of "illegal imprisonment" and handed down sentences ranging from several months to a year and a half. The article said officers from the Beijing Municipal Public Security Bureau had helped round up the retrievers in early May.
"Insiders suggest the case has evident positive significance because it says 'no' to local governments that want only to restrict people's personal freedom in the name of stopping petitioners," the article said. "The case will also serve as a warning to Beijing's black jails."
Judging from many of the thousands of comments posted online, few believed the official retraction. "The news was on People's Daily Web site," said one. "Is People's Daily a rumor mill?"
Another said, "The news might be false, but people's voice is real."
Mia Li contributed research.
Correction: December 2, 2012, Sunday
This article has been revised to reflect the following correction: A previous version of this article incorrectly stated that officers from the Beijing Municipal Public Security Bureau had helped round up petitioners. They helped round up the "retrievers" who had grabbed petitioners off the street.
This article originally appeared in The New York Times.