Nutra Trulock, who was director and, recently, deputy director, of intelligence at the US Energy Department, accused the Clinton administration of sweeping the scandal under the carpet and refusing to hold senior officials accountable.
In interviews with two US newspapers, Mr Trulock also denied "categorically" that race had had anything to do with the charges he had levelled against Wen Ho Lee, the Taiwanese-born weapons designer named as the chief suspect in the case.
Mr Lee was dismissed from his job in March after reportedly failing to co-operate with the FBI and failing two lie detector tests. He was the only Asian-American in his top-secret design team and said he had been singled out unfairly because of his Chinese ethnicity. The FBI has said he is unlikely to face spying charges for lack of evidence.
The trigger for Mr Trulock's resignation was a report by the inspector general of the Energy Department, released last week, which failed to support his claim of widespread Chinese spying at US nuclear laboratories, including Los Alamos. This was the second investigation to have found little evidence of a Chinese penetration of the Los Alamos laboratory or of Mr Lee's involvement.
The former head of counter-intelligence at Los Alamos, Robert Vrooman, said last week there was "not a shred of evidence" that Mr Lee had spied for China. He said Mr Lee had been accused largely because he was born in Taiwan and had contacts in China.
He also also challenged the view that China had obtained the blueprints for the highly confidential W-88 miniaturised warhead from Los Alamos. Chinese officials have been unusually adamant in denying the theft of the technology, insisting that any information came from scientific publications or the Internet.
Mr Vrooman's remarks could be read as self-defence - he was one of three senior Los Alamos officials disciplined last week for security breaches. But a colleague of Mr Lee's, Michael Soukup, told the Washington Post yesterday that he also fitted the profile of the presumed spy. Mr Soukup had access to the secrets, had visited China and had exchanges with Chinese laboratories - but he had not been questioned. He is not Asian.
The main charge remaining against Mr Lee is that he transferred secret files from his high-security computer to a less secure computer in the same laboratory, a practice that he described as common.Mr Lee and his lawyer were reportedly in discussions with the Justice Department amid speculation that the administration was seeking a face- saving exit for all concerned.
An analysis by Newsweek magazine this week, however, concluded that if anyone was likely to take anyone to court, it would be Mr Lee suing the US government.Reuse content