National Institutes of Health (search) investigators have cleared up to 80 percent of its researchers suspected of secret deals with pharmaceutical and biotechnology companies, officials say.

NIH officials found errors by government investigators had led to as many as 80 of an estimated 100 researchers being mistakenly implicated in a federal probe of consulting arrangements, The Washington Post reported in Wednesday's editions.

A congressional committee had found that about 100 NIH scientists had failed to notify the agency about their outside deals, as required.

However, the Post reported, a detailed NIH review found that 50 percent to 80 percent of the scientists had followed the requirement but were implicated by mistake because of confusion over similar names, the time period for which data were collected and differences in data coding.

Based on the initial finding that scores of researchers had kept their ties with companies secret, NIH Director Elias A. Zerhouni (search) severely restricted the personal activities and finances of the agency's 5,000-plus employees.

That forced thousands of employees and their families to sell stock and banned scientists from accepting professorships and board positions with professional societies, even if uncompensated and using their own time.