By Ian Simpson
WASHINGTON (Reuters) - House Republican investigators fault top Internal Revenue Service officials for mistreating conservative organizations who sought tax-exempt status, but have found no connection to the White House, according to an interim report released on Tuesday.
The report from the House Oversight and Government Reform Committee came after investigators went through 1.3 million pages of documents and interviewed 52 officials.
The report came at the end of Republican Representative Darrell Issa's tenure as head of the oversight panel. Issa has clashed with congressional Democrats and the White House over the IRS' treatment of conservative groups.
The report, the sixth by Issa's committee since September 2013, said tea party and other conservative groups were improperly targeted by the IRS from 2010 to 2012. It also said IRS officials covered up the misconduct and misled Congress about it.
Eight IRS executives "were in a position to prevent or to stop the IRS's targeting of conservative applicants," the report said.
They include former Commissioner Douglas Shulman, former acting Commissioner Steven Miller, and Lois Lerner, the former head of the unit that processes applications for tax-exempt status.
The report also said the IRS and the White House had not fully cooperated with the investigation.
Shulman's term as IRS commissioner ended before the controversy erupted in spring 2013. President Barack Obama, a Democrat, forced Miller to resign after Lerner acknowledged that conservative groups had been mistreated. She has since retired.
The IRS had no immediate response to a request for comment.
Issa will be replaced in January as head of the oversight panel by Jason Chaffetz of Utah when a new Congress convenes in January.
Representative Elijah Cummings of Maryland, the ranking Democrat on the committee, criticized release of the interim report.
Republicans "are leaking cherry-picked excerpts of documents to support their preconceived political narrative without allowing committee members to even see their conclusions or vote on them first," he said in a statement.
(Reporting by Ian Simpson; Editing by Bill Trott)