The former chairman of the Corporation for Public Broadcasting interfered with PBS programming and appeared to employ "political tests" in the hiring of the corporation's new president, internal investigators reported Tuesday.

Kenneth Y. Tomlinson, a Republican, also sought to withhold funding from PBS unless the taxpayer-supported network "balanced their programming" with more conservative voices, said the report by corporation inspector general Kenneth A. Konz.

Tomlinson was chairman of the corporation until September and resigned as a board member earlier this month after Konz privately shared his findings with the board. The report was publicly released Tuesday.

The corporation, which funnels hundreds of millions of federal dollars to National Public Radio, the Public Broadcasting Service and other noncommercial radio and television stations, was set up by Congress in 1967 to shield public broadcasting from political influence.

Democrats in Congress and other supporters of political broadcasting had complained that Tomlinson was stacking the corporation with Republicans, meddling in programming and trying to turn public radio and TV into a mouthpiece for the GOP.

Specifically, the report said Tomlinson violated federal rules and ethical standards by dealing directly with one of the creators of the conservative-leaning "Journal Editorial Report," hosted by the editor of The Wall Street Journal editorial page.

There was also evidence, the report said, to suggest that "political tests" or qualifications were used as a major factor in the hiring of new CPB President Patricia S. Harrison, also in violation of federal rules.

Tomlinson has defended his actions as an effort to bring political balance to public-affairs programming and maintained no wrongdoing as corporation chairman.