BEIJING — For a nation not yet inured to lurid and senseless crime, a report that a former civil servant in central China kept six women enslaved in an underground bunker — and that he killed two of them — was shocking enough.

But perhaps almost as disturbing, at least to some readers, was that the journalist who exposed the crime more than two weeks after the suspect’s arrest was detained by security agents who accused him of revealing state secrets.

After his release from questioning on Thursday, the reporter, Ji Xuguang, wrote an article that accused the authorities of trying to keep the public in the dark about a heinous crime that unfolded less than two miles from the city’s public security bureau.

“I was only thinking about how to make my story as accurate as possible and to satisfy the public’s right to know, but I soon discovered that I failed to address the most important issue — face,” wrote Mr. Ji, a reporter for Southern Metropolis Daily, one of the country’s most aggressively independent publications. “Before the truth becomes a state secret, the public and myself need answers.”