Washington (CNN) -- The vice chairman of the Federal Election Commission told CNN on Monday he has seen numerous undisclosed e-mails between FEC staffers and the Internal Revenue Service that raise new questions about potential improper contact between two federal agencies in the alleged targeting of conservative political groups.
Don McGahn, a Republican FEC commissioner, said an investigator from his agency contacted Lois Lerner, the IRS employee at the center of the political storm now engulfing that agency.
He said the contact was made to discuss the status of one such conservative political advocacy group, the American Future Fund.
Shortly after Lerner was contacted, the IRS sent a questionnaire to the American Future Fund, McGahn added.
"Who's the dog and who's the tail (in this case)? Who knows," McGahn said. But "dealing with Lois Lerner is probably out of the ordinary."
The answers, McGahn stressed, "could be benign (or) could be more sinister."
McGahn, who did not provide a timeline of events, said FEC commissioners had not given their staffers permission to reach out to the IRS on the matter, which is generally required for such inquiries.
The e-mails McGahn described to CNN are exactly what Republican congressional investigators are asking IRS and FEC officials to turn over to Congress as part of its investigation.
Ellen L. Weintraub, the Democratic chairwoman of the FEC, said she does not know about the e-mails between the FEC investigator and Lerner to which McGahn is referring.
"If there was any evidence or targeting based on ideology, that would be extremely serious, but I have not seen any evidence of that," she said.
"I am not aware of requesting or receiving any confidential taxpayer information. I am not aware of any requests for anything that wasn't publicly available."
Last week, congressional Republicans disclosed several e-mails between Lerner, the former head of the IRS division handling tax exempt organizations, and an unnamed FEC attorney inquiring about the status of the American Future Fund and another conservative outfit, the American Issues Project.
The e-mails were first uncovered by House Ways and Means Committee Chairman Dave Camp, R-Michigan, who sent a letter last week to acting IRS Commissioner Daniel Werfel requesting additional details regarding exchanges between Lerner and the FEC.
The e-mails that congressional Republicans released only reference and request publicly available information on the two groups. McGahn told CNN, however, that the additional e-mails he has seen do not clearly state whether the FEC was only seeking public data. Asking for private data would most likely be a violation of federal law.
McGahn was not able to specify whether contact was initiated by Lerner or the FEC, which regulates political speech and handles numerous complaints every election cycle about alleged violations of its campaign rules and regulations.
Contacted by CNN on Monday, the IRS emphasized that the agency "takes its obligation to protect confidential taxpayer information very seriously."
An IRS spokeswoman noted that the agency is prohibited from discussing information contained in specific tax returns.
Republicans -- led by House Oversight Committee Chairman Darrell Issa -- insist that after President Barack Obama's 2008 election, the IRS started intentionally targeting conservative outfits seeking tax-exempt status.
The prospect of potential FEC involvement raises the prospect of a broader federal targeting effort.
Democrats argue there is nothing sinister and that the contact is nothing more than requests for information that is already in the public domain.
Still, Republicans question why FEC staffers would bother contacting Lerner -- herself a former FEC employee -- for information already publicly available.
Lerner made headlines after she invoked her Fifth Amendment right against self-incrimination when called before the House Oversight Committee in May to testify on the controversy.
"Things seemed weird to me" after examining the undisclosed e-mails, McGahn told CNN. "The FEC has not had a good track record with calling balls and strikes. They've been criticized for not playing fair."
If nothing else, he added, this "creates the appearance that people are being selectively targeted. And that's something that should never happen."
American Future Fund founder Nick Ryan argued in a written statement last week that the publicly released correspondence between the IRS and the FEC "indicates questionable behavior."
"We will cooperate with (the) ongoing investigations to root out the bad actors in the politically driven, out-of-control bureaucracy the IRS and the government has become."
For their part, Democrats have dismissed the latest revelations and insist groups on both the left and the right were improperly scrutinized as part of a clumsy administration of vague election-related tax laws.
"House Republicans are doing everything they can to distract attention from their inability to focus on jobs and the economy," said Josh Drobnyk, a spokesman for Democrats on the House Ways and Means Committee, which is also investigating the alleged targeting.
"Republicans are throwing mud against the wall with the hope that some will stick."
To date, Republican-led IRS investigations of tea party targeting have uncovered no evidence any of it was directed by Obama political officials.