LOS ANGELES (REUTERS) - Breaking a long silence, a politically connected Chinese businessman living in the United States has denied through his attorney that he handed over Chinese state secrets, including launch codes for nuclear weapons, to US authorities.

Ling Wancheng, brother of a former top aide to ex-Chinese President Hu Jintao, was the subject of media reports last week asserting he had been debriefed by US officials and provided nuclear secrets as well as personal information about Chinese leaders.

His case has generated intense interest in China and the US because of the access Ling Wancheng's brother, Ling Jihua, once had to the inner workings of China's Communist Party leadership.

Gregory Smith, a Washington attorney and former associate White House counsel to President Bill Clinton, said he has been retained by Ling Wancheng. He said that Ling Wancheng is in the United States but declined to say whether his client has applied for asylum and whether he is talking to US authorities.

Ling Wancheng had not previously issued any statements or confirmed that he remained in the US or was represented by counsel.

Smith, speaking by telephone from his Washington office, said Ling Wancheng was upset by the recent allegations. They had appeared in the Washington Free Beacon and later in the Financial Times.

Smith said he had been authorised by Ling Wancheng to make the following statement: "The absurd rumours that he is in possession of a large number of secrets, including keyboard nuclear codes, and rumours that he has handed over state secrets to the US government, reported by media outlets, is a baseless lie and a groundless defamation, and he reserves his right through me to take action as appropriate."

Smith added that his client, an avid golfer, "came to the US to share golf secrets, not state secrets".

Bill Gertz, senior editor at the Washington Free Beacon and author of a Feb 3 article that Ling Wancheng disputes, said of Ling Wancheng's denials: "I have no comment." The Financial Times did not respond to e-mail requests for comment.

Ling Wancheng's older brother, Ling Jihua, was once head of the Communist Party's General Office of the Central Committee, a powerful job similar to that of a cabinet secretary in Western Westminster-style governments. In that position, he would have had access to information about the Chinese government's inner workings.

Ling Jihua was expelled from the party last year, becoming one of the highest-profile targets of an anti-corruption campaign launched by President Xi Jinping. Ling Jihua is now awaiting trial on bribery and other charges.

"One presumes he (Ling Wancheng) is a valuable asset," said Christopher Johnson, a former senior Central Intelligence Agency China analyst who is now at the Centre for Strategic and International Studies in Washington.

"His brother was certainly in a very sensitive position in China, and would have had access to some very sensitive information. How much and to what degree did he pass this information on to his brother? That is the big question."

US officials have consistently declined to answer questions about Ling Wancheng, including whether he has applied for asylum and whether he has been debriefed by government agents.

Jennifer D. Elzea, of US Immigration and Customs Enforcement, the government department that deals with asylum applications, said the department does not confirm or deny asylum applications because of strict confidentiality rules governing the process.

A US State Department official declined to comment on any agency dealings with China over Ling Wancheng. The official said the State Department regularly engages with China on law enforcement matters, and China has raised a number of specific cases of concern.

Marc Raimondi, national security spokesman at the US Department of Justice, declined comment.

China's Foreign Ministry declined to comment on Ling Wancheng, saying the issue was not within its purview. China's Central Commission for Discipline Inspection, which handles investigations around corruption, did not respond to a request for comment.