White House press secretary Jay Carney speaks to reporters about the so-called "sequester" at the White House in Washington February 28, 2013. (Credit: REUTERS/Kevin Lamarque)

Senior White House officials, including Chief of Staff Denis McDonough, learned last month about a review by the Treasury Department’s inspector general into whether the Internal Revenue Service targeted conservative groups seeking tax-exempt status, but they did not inform President Obama, the White House said Monday.

The acknowledgement is the White House's latest disclosure in a piecemeal, sometimes confusing release of details concerning the extent to which White House officials knew of the IG’s findings that IRS officials engaged in the “inappropriate” targeting of conservative non-profits for heightened scrutiny. Previously, the White House said counsel Kathryn Ruemmler did not learn about the final results of the investigation until the week of April 22nd, and had not disclosed that McDonough and other aides had also been told about the investigation. On Monday, White House Spokesman Jay Carney said a member of Ruemmler's staff learned of the probe the week of April 16; Ruemmler learned of the investigation on April 24th; and after that point she informed the chief of staff and other aides about the probe's findings.