Thievery and cheating on physician licensing tests are so rampant that applicants soon will be monitored in individual rooms with hidden video cameras that can record and time every move, according to medical testing groups.

At a special meeting of medical boards here, testing groups announced a series of moves they say are needed to restore the integrity of U.S. medical credentials.

In recent years, nearly all the key tests required for licenses have been sold illegally in advance, for up to $50,000 per copy in some cases. In other cases applicants have used sophisticated crib sheets, have copied test questions to sell later, or have paid imposters to take the test for them.

As a result, the National Board of Medical Examiners, which oversees the national tests that all U.S.-trained doctors must pass, announced an end to its paper-and-pencil exams for the final segment of its three-part test by 1988, changing to computers. The first two parts will be computerized during the next several years, possibly by 1990, the board said.

By 1988, the 13,000 first-year medical residents who take the exams each year will be seated in individual rooms monitored by video cameras hidden in the ceiling.

"We believe it will encourage appropriate examinee behavior," said Barbara Andrew, vice president of the national board. "As long as we disclose the monitoring in advance, we don't expect any problems."

The tests are given twice yearly in 130 locations. The board opened its prototype computer test center in Philadelphia last month and plans to add seven others across the country in the next three years.

The computer test, which requires candidates to volunteer information and analyze illustrations on a video screen, also is designed to weed out candidates with poor training who may be passing the current test of multiple-choice questions, said Dax Taylor, another vice president.

To further protect the testing process, instead of paper tests being sent to centers across the country, the material will be transmitted over telephone lines in code. "Even if someone tapped in, it would simply be gibberish," said Andrew. "Our security consultants say it would take many computers and many years to decode the tests."

Medical testing groups have been taking crash courses in security measures since the Federal Bureau of Investigation declared last year that the tests certifying foreign-trained physicians to practice in the United States had been "compromised" in every large U.S. city.

To combat this, the Federation of State Medical Boards, which administers its Flex test yearly to about 15,000 foreign-trained medical graduates, has designed a new test and security measures to begin this July.

A second test required for foreign-trained physicians -- given by the Educational Commission for Foreign Medical Graduates -- also has been revamped this year to make it more rigorous. In investigating phony medical diploma schemes, U.S. postal authorities found that many of the bogus doctors had been able to pass the licensing exams with little or no medical training.