Lois Lerner, the former IRS official accused of targeting conservative non-profit groups, is longtime friends with a Wisconsin state regulator who helped local prosecutors investigate aides and conservative allies of Gov. Scott Walker.

The Wall Street Journal reports in an editorial that Lerner and Kevin Kennedy, the director of the Wisconsin Government Accountability Board (GAB), were in routine contact via email between 2011 and 2013.

Emails viewed by The Journal show that the two regulators discussed issues ranging from the personal to political. They shared news articles about campaign finance and also discussed dinner plans. The pair have known each other for more than 20 years, Kennedy told The Journal.

The revelation raises questions over whether Lerner and Kennedy coordinated in any way in their investigations.

Kennedy helped the Milwaukee County district attorney and prosecutors in several other counties conduct a wide-ranging, multi-year investigation into whether Walker’s gubernatorial campaigns illegally colluded with outside conservative groups. The investigation was sparked after Democrats in the state lost an election to recall Walker and senate Republicans after they busted state employee unions.

The investigation, which has been halted by a judge, saw the homes of Walker associates raided in the middle of the night. Secret subpoenas were filed allowing investigators to obtain phone, text message and email records of conservatives. Many of those targeted in the investigation were never made aware that they were being scrutinized.

Under Kennedy’s stead, GAB hired four investigators to take part in the probe. It also devoted staff to the investigation. The Wisconsin Club for Growth, which was one of the targeted groups, alleged last year that Kennedy cooperated in the investigation for months before getting approval from the six retired judges that sit on GAB’s board. The Club for Growth also asserted that after the board voted that GAB should stop aiding the investigation, staffers with the regulatory agency continued to do so anyway.

According to the Milwaukee Journal Sentinel, Kennedy’s GAB considered subpoenaing Fox News’ Sean Hannity and local radio host Charlie Sykes as part of the probe.

At the same time that Kennedy’s agency was taking part in the Walker witch-hunt, Lerner was directing the IRS’s Exemptions division, which handled applications from organizations seeking non-profit status. Some conservative groups have alleged that they were unfairly audited and investigating after applying for tax exemption. Congressional investigations into whether the audits were politically-motivated have been stymied by the IRS and Lerner.

The Journal points to another connection between the Walker investigation and the IRS.

Sources tell us that in 2012 and 2013 John Doe investigators asked the IRS to look into a conservative group that was among the primary targets of the Wisconsin Doe investigation. The IRS doesn’t appear to have followed up, but the request shows Wisconsin prosecutors saw their pursuit of independent groups as part of a common agenda with national Democrats.

After The Journal’s editorial appeared, Wisconsin state lawmakers called on Kennedy to resign.

“Friday’s Wall Street Journal exposed a coordinated effort by the GAB’s Kevin Kennedy and the disgraced Obama appointee at the IRS Lois Lerner,” reads a joint statement from Republican state senator Alberta Darling and representative John Nygren.

“It is clear that the harassment of conservative groups by Lerner at the federal level directly coincided with the harassment of conservative groups right here in our state.”

Follow Chuck on Twitter