During World War II, the Japanese experimentally killed about 3,000 humans, including American prisoners of war, with biological weapons and the U.S. military establishment made a secret arrangement with the Japanese to hide the experiments, according to an article in the current issue of the Bulletin of the Atomic Scientists.

The Americans entered into the agreement, which included arguments in favor of granting immunity from war crimes prosecution to the responsible officers, so that America could make use of the results from the gruesome tests, the article's author says.

The victims were used as experimental animals and eventually killed in Japanese biological warfare experiments, which included employing massive doses of plague, anthrax and smallpox germs. The Japanese also killed by other grotesque means, such as radiation poisoning, pumping victims full of horse blood or cutting them up while alive, the article says.

John Powell, the author, quotes half a dozen documents on the secret bargain between the responsible Japanese and American military authorities. Powell said he obtained numerous documents on the arrangement from the Defense Department through requests under the Freedom of Information Act.

Those official records indicate that the Americans who made the bargain were aware that U.S. soldiers were killed in the experiments, the article says, thus raising "disturbing questions about the role of numerous highly placed American officials at the time."

The Army had no comment on the report.

There is apparently no good estimate of the number of Americans involved in the experiments, or any names. Powell speculated that the military did not want to press any such questions for fear that the whole matter would become public.

Previous reports over the years have confirmed the existence of a very sophisticated Japanese biological warfare program, as well as a large number of casualties in the three Japanese camps where the work was carried out under the direction of Japanese Lt. Gen. Ishii Shiro.

A secret cable from Tokyo to Washington on May 6, 1947, relayed Gen. Ishii's offer to supply full information about the experiments in return for guaranteed immunity against trial for war crimes.

According to the documents quoted by Powell, the information obtained from Gen. Ishii was "invaluable" and could not be obtained in any other way by the United States "because of scruples attached to human experimentation." The documents also argued that the information was cheap, costing "a mere pittance compared with the actual cost" to the Japanese of carrying on the gruesome work.

A later memo by two American officials, Dr. Edward Wetter and H. I. Stubblefield, said that Gen. Ishii was beginning to supply the desired materials, including "selected samples of 8,000 slides of tissues from autopsies of humans and animals subjected to BW biological warfare experiments."

The memo said that "since any war crimes trial would completely reveal such data to all nations, it is felt that such publicity must be avoided in the interests of defense and national security of the U.S."

A large variety of experiments apparently were carried out on the human prisoners. In some cases, after a prisoner was infected, the disease was allowed to run its course for some time and then the prisoner was "sacrificed" so that an autopsy could be done to see the extent of the damage caused by the biological agent.

A report in December, 1947, from Edwin V. Hill, chief of basic sciences at Camp Detrick (later Ft. Detrick), Md., noted the great value of the results of the experiments and said of the Japanese: "It is hoped that individuals who voluntarily contributed this information will be spared embarrassment because of it and that every effort will be taken to prevent this information from falling into other hands."

Another memo, from U.S. headquarters in Tokyo, said the advantages of granting the Japanese "immunity from war crimes" was that it would "result in exploiting 20 years' experience of the director, General Ishii, who can assure complete cooperation of his former subordinates."

Powell said that Gen. Ishii and many of his staff lived out full lives in Japan and died of old age. But a few of them are still alive and living in quiet retirement in Japan.