The Associated Press has learned that fewer than half of Veterans Affairs clinics given a surprise inspection last month followed proper standards for colonoscopies and other minimally invasive procedures — even after the agency learned that mistakes may have exposed thousands of veterans to HIV and other diseases.

The VA's findings, obtained by the AP, suggest that errors in colonoscopies and other procedures performed at VA facilities may be more widespread than initially believed.

The report will be released at a House hearing Tuesday.

Since February, the VA has told some 10,000 patients in three states to get tested. More than 50 patients tested positive for infections, including six for HIV. It can't be proven that their infections came from the procedures.