Over the past 20 years China has stolen the technology for all the US nuclear warheads, and this spying is "almost certainly" continuing, according to a startling new report.
The report, by a Congressional select committee, has led to calls for the resignation of President Clinton's national security adviser, Mr Sandy Berger, and the Attorney General, Ms Janet Reno. However, the White House has rejected such calls and pointed out that Chinese espionage at the nuclear laboratories also took place under Republican presidents who, unlike President Clinton, took no countermeasures.
China's acquisition of the technology for the most advanced nuclear warheads used by US missiles was only discovered during President Clinton's first term in 1995 through a Chinese defector. The President and his advisers are being criticised for not taking sufficient precautions once the leaks were discovered.
The White House has for months been opposing the declassification of the report, which was completed by a bipartisan panel headed by Republican Congressman Christopher Cox at the end of last year. About 70 per cent of the report was released yesterday.
In Beijing, an official at the Chinese Defence Ministry denied that China had stolen any secrets from the US or any other country.
Although some of the contents of the report had leaked already in Washington, the extent of China's possession of US nuclear secrets caused widespread shock and is being compared with the Soviet Union stealing atomic bomb secrets in the 1940s.
Congressman Norm Dicks, the senior Democrat on the committee, said the 700-page report documented "one of the worst counterintelligence failures in the nation's history".
In addition to learning secrets about the seven nuclear warheads deployed by the US, China is also said to have stolen the design of the so-called "neutron bomb" which can kill people without damaging buildings. Two US companies are also accused of allowing China acquire secret missile technology for satellite launches.
President Clinton, trying to repair the damage in Sino-US relations caused by the bombing of the Chinese embassy in Belgrade earlier this month, said he would implement most of the recommendations of the report but would also continue his policy of "engagement" with China because it was in the national interest.
The President said that "like many other countries, China seeks to acquire our sensitive information and technology" but the US had a "solemn obligation" to prevent this. He had ordered a "sweeping reorganisation" of security at the nuclear laboratories in February 1998.