Three months after the Chinese president's plane was found bugged, the country has not issued a formal complaint with the U.S., a former government official with close ties to the current White House administration said.

The source said a Chinese official in Beijing told him Friday that there had been no formal protest — which experts said suggests the possibility that Chinese authorities have reason to suspect their own people played a role in the episode.

The source also said he believed the discovery would have no lasting impact on U.S.-China relations.

The White House and State Department kept mum on the matter, declining to answer questions about Beijing's reaction.

"We never discuss these kinds of allegations," said White House spokesman Taylor Gross.

Washington wouldn't disclose whether the Chinese had objected to the bugging of the aircraft or otherwise offer comments on the matter. In fact, it was generally understood that there was no communication involving either administration.

Newspaper reports Saturday said Chinese authorities discovered the bugs during a test flight last October.

U.S.-China relations have been topsy-turvy in recent years, and controversy over spying is not new. Last April, a Chinese fighter intercepted and collided with a U.S. Navy EP-3E surveillance plane over the South China Sea, forcing the Navy plane to make an emergency landing on a Chinese island. The fighter jet crashed, killing its pilot.

The Navy plane had been collecting electronic intelligence on the Chinese military, and China protested that such missions were violating its national sovereignty. China released the EP-3E crew only after the Bush administration publicly stated it was sorry for what happened.

The Washington Post quoted unidentified sources as saying Chinese aviation and military officers believe U.S. intelligence agencies planted the listening devices aboard the plane while it was being fitted in the United States with special bathroom and other accommodations for President Jiang Zemin. The CIA had no comment.

The Post reported that after the listening devices were discovered, 20 Chinese air force officers and two officials involved in negotiations for the airliner were detained and are being investigated for negligence and corruption. It also said a senior air force officer is under house arrest for his role.

The Chinese government made no public comment on the matter.

The Financial Times of London reported that tiny listening devices were hidden in the jetliner's upholstery, including in the president's bathroom and the headboard of his bed. It cited unnamed Chinese sources.

State Department spokesman Richard Boucher, who was traveling with Secretary of State Colin Powell in Tokyo on Saturday, said he was aware of the news reports but declined comment. In Washington, department spokeswoman Brenda Greenberg had no comment on whether China had lodged a diplomatic protest.

Bates Gill, a China expert at the Brookings Institution think tank, said Saturday that if the bugs were found before the plane went into use as Jiang's personal aircraft, China's intelligence loss would be minimal and the scandal would probably blow over fairly quickly.

"My sense is this will not have any lasting effects" on U.S.-China relations, Gill said. "This can, in a relatively short period of time, be set aside as simply a failed intelligence operation. In fact it shouldn't surprise anyone in the United States or China that someone is trying to collect intelligence."

Chinese officials were puzzled as to how and when the bugs were planted, the newspaper reports said. China had carefully monitored the plane's construction at the Boeing Co. plant in Seattle, and the fitting of its interior by several aircraft maintenance companies in San Antonio, Texas.

The disclosure comes one month before President Bush is scheduled to travel to Beijing to meet with Jiang.

Bush was at the Camp David, Md., presidential retreat Saturday and received his usual intelligence briefing.

The Associated Press contributed to this report.