It is unclear what kind of information the detained Chinese official is suspected of having given to the United States and whether that information has compromised any operations by the Chinese government. Recently, news of the spying suspect’s detention had been circulating quietly in some foreign intelligence circles. A spokesman for the American Embassy in Beijing declined to comment.

Secretary of State Hillary Rodham Clinton, visiting Oslo on Friday, declined to comment on the reports of an espionage arrest, as did officials at the State Department and the White House in Washington.

A senior administration official, speaking on the condition of anonymity because of diplomatic sensitivities, said the detention came during the same period as a series of investigations begun after the revelations in the Bo affair. The investigations, authorized by China’s top leaders, have expanded beyond Mr. Bo to the Ministry of State Security and now include allegations of improper use of the security services by various Chinese officials and corruption, the official said.

It was not clear that the espionage case was related in any way to the other investigations.

“There is clearly some very intense stuff going on with the security ministry,” the official said. “It’s hard to tell exactly, but it’s clearly maneuvering going on after Bo.”

Early this year, senior Chinese officials imposed a foreign travel ban on scholars at an important research center based in Beijing that some analysts say has ties to the Ministry of State Security. The ban on overseas travel within the center, the China Institutes of Contemporary International Relations, was related to an intelligence breach, said one person who has contact with the institutes’ scholars, and could well be a direct result of the discovery and detention of the official suspected of spying.