New documents released Tuesday cast doubt on allegations that the Internal Revenue Service targeted conservative groups to aid President Barack Obama.

House Oversight Committee Chairman Darrell Issa (R-CA) and other Republicans have alleged that IRS officials inappropriately flagged conservative groups that were seeking tax-exempt status for additional scrutiny because they were seen as enemies of Obama.

Rep. Elijah E. Cummings (D-MD), Ranking Member of the House Oversight Committee, released a 36-page memo (PDF) on Tuesday that included excepts from the committee's 15 interviews of IRS employees involved in the screening of tax-exempt organizations.

A tax law specialist -- who registered as a Republican -- told congressional investigators it was "laughable that people think" the IRS targeted Obama's enemies. She worked in the Washington, D.C. office of the IRS on several applications from tea party groups and said the IRS was concerned about "political campaign intervention activities" but lacked the guidance needed to process the applications because the law was ambiguous.

"And so the lingering length of time, unfortunately, was just trying to apply the law to the specific facts of each case," she explained.

Several other IRS employees, both Democrats and Republicans, said they received no guidance from the White House. The IRS flagged tea party groups, the employees claimed, so their applications would receive consistent treatment.

Democrats have released a growing list of documents that cast doubt on the IRS scandal, which began in May after the Treasury Inspector General for Tax Administration (TIGTA) published an audit that concluded the IRS used "inappropriate criteria" to flag tea party groups for additional review. Republicans quickly decried the findings and launched several congressional investigations.

Democrats later published the so-called "Be On the Look Out" (BOLO) memos mentioned in the audit, which showed liberal and progressive groups were also targeted.

But Republicans alleged that the party groups were automatically flagged for review, while progressive groups were not. However, a 2010 IRS presentation (PDF) on how to screen tax-exempt applications stated progressive groups and others "were of interest and should be flagged for review." The presentation instructed screeners to "err on the side of caution" and flag all potential political groups for review.

An internal email sent in May by TIGTA's Head of Investigations specifically stated the IRS did not target conservative groups. An investigation of 5,500 IRS emails showed the tea party was placed on the BOLO memos because "the IRS employees were not sure how to process them, not because they wanted to stall or hinder the application," the top investigator wrote.

It is unclear why that finding, which the Head of Investigations described as "very important," was not included in the audit.

"This new information underscores the fact that the Treasury Inspector General’s audit was fundamentally flawed and created widespread misperceptions that Republicans seized on in an effort to attack the White House. It is now all the more important that Inspector General George return to Congress to explain his glaring omissions and reasons for releasing a highly misleading report," Sander Levin (D-MI) said last week.