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.