An ongoing House Ways and Means Committee probe of the IRS scandal has uncovered proof that the agency demanded donor lists almost exclusively from conservative groups and could make them public despite promises to destroy the sensitive tallies of contributors.

Committee officials told Secrets that of the 27 groups forced to cough up donor lists, 24 were conservative, nearly double the number suggested previously by IRS management. At a recent committee hearing, former acting Internal Revenue Service boss Steven Miller said that a majority of the requests were to non-Tea Party groups.

Previously, Democrats have suggested that progressive groups were targeted in similar numbers.

The IRS had pledged to the committee to destroy the donor lists, which were improperly requested. If kept in the files, they become public.

However, the committee told Secrets that in the 300,000 pages its reviewed so far, donor lists remain in some of the case files of the groups. “That will become part of the public record,” said a committee official.

Many of the Tea Party groups whose tax exempt requests were politically scrutinized and held up in the scandal were classified as 501 [c] 4 organizations. Those do not have to reveal their donors because donations are not tax deductible. Some groups fear that making donors public will scare future contributors away.

The issue is expected to come up at a Wednesday committee hearing featuring acting IRS Commissioner Daniel Werfel.

Paul Bedard, The Washington Examiner's "Washington Secrets" columnist, can be contacted at