Lois G. Lerner, the embattled Internal Revenue Service official who apologized for improperly scrutinizing the tax-exempt status of conservative nonprofit groups, is a member of the Humane Society of the United States, a liberal animal advocacy organization.

Lerner — the suddenly infamous IRS Exempt Organizations Division director — “is an active member of the Humane Society of the United States where her efforts in performing pet rescues necessitated by the 2005 Gulf Coast hurricanes were widely acknowledged,” according to her biography.

The HSUS has been accused of sending less than one percent of its funds to animal shelters, a charge that a spokesman in 2012 would not deny. According to IRS filings, the group took in $148,703,820 in revenue in 2010.

On May 12, 2010, Republican Missouri Rep. Blaine Luetkemeyer wrote a letter to Lerner, expressing his concerns about the tax-exempt status of the HSUS, which is listed as a 501(c)(3) nonprofit group.

“The attached information unquestionably demonstrates that [the] HSUS invests a substantial amount of time and money in political campaigns and attempts to influence specific legislation, a clear and direct violation of section 501(c)(3) of the Internal Revenue Code,” Luetkemeyer wrote in the letter.

“I understand that you are not at liberty to comment on any potential IRS actions but do hope your agency will give thoughtful consideration of the concerns I have expressed,” Luetkemeyer wrote.

Lerner has been unresponsive to Luetkemeyer’s office’s repeated requests for status updates on the matter over the past three years.

“This was actually the result of concerns from constituents at the time that [the] HSUS was involved in political activity,” Luetkemeyer spokesman Paul Sloca told The Daily Caller Thursday.

“Since then, over the past three years, we’ve been in contact with Treasury, and with Ms. Lerner, on this issue,” Sloca said. “They have told us they can’t comment on an ongoing investigation, but they haven’t been able to confirm that they’ve even launched an investigation.”

“They won’t confirm that there is an investigation going on. They haven’t provided any substantive information,” he said.

“Considering the current news about the IRS, this is definitely something the congressman is definitely going to follow up on,” Sloca concluded.

By the time Luetkemeyer sent his letter to Lerner in May 2010, the IRS had already begun targeting conservative nonprofit groups for extra scrutiny, according to a report released Tuesday night by the Treasury Inspector General.

Lerner did not respond to TheDC’s request for comment for this report.

The Humane Society of the United States declined comment.

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This report has been updated.