A new secret John Doe investigation has been launched in Milwaukee County looking into possible campaign violations related to a legislative leader and the governor’s race, a newspaper is reporting.

The State Journal confirmed the existence of a sealed John Doe investigation, first reported by the Milwaukee Journal Sentinel on Monday, that was launched in February 2012 and is being overseen by Kenosha County Circuit Judge Barbara Kluka.

“It’s pretty clear that they’re diving deep and long, and will take their time,” said Paul Bucher, a Republican and former Waukesha County District Attorney who said he is aware of the investigation’s scope.

Several legislative leaders or their spokesmen contacted by the State Journal — including Assembly Speaker Robin Vos, R-Rochester, Assembly Minority Leader Peter Barca, D-Kenosha, and Senate Minority Leader Chris Larson, D-Milwaukee — said they had not heard about the investigation until reading about it in the Journal Sentinel.

Patrick Guarasci, a consultant for the campaign team for Milwaukee Mayor Tom Barrett, Gov. Scott Walker’s opponent in the 2010 election and the 2012 recall, said the same.

When pressed about the matter, Dan Romportl, chief of staff for Senate Majority Leader Scott Fitzgerald, R-Juneau, declined to discuss the newspaper’s report.

“Sen. Fitzgerald does not have any comment at this time regarding the Journal Sentinel article,” Romportl said.

Walker also refused to discuss the probe Monday or say whether anyone on his staff or campaign has been contacted by prosecutors, calling it a “sidebar issue.”

“I’m not going to get pulled into that, one way or another. Because if somebody was (contacted) and they said they were, they’d be in violation of that,” Walker said, in apparent reference to the secrecy order that commonly accompanies such investigations. “If they weren’t, they’d be speculating on something that they’re not involved in. So either way, it doesn’t make any sense to get involved with that.”

According to the Journal Sentinel, the investigation led by a former federal prosecutor spans five counties, including Dane, has been going on for 19 months and may be related to recall campaigns, but the report did not name any particular campaign.

In 2011 and 2012, 13 state senators — three Democrats and 10 Republicans, including Fitzgerald — were forced to defend their seats in a wave of recall elections.

The recalls were sparked by the fight over Act 10, Walker’s signature legislation abolishing most collective bargaining rights for most public employees in Wisconsin.

According to unnamed sources quoted by the Journal Sentinel, the current probe is an outgrowth of the now-closed John Doe investigation that resulted in criminal convictions for illegal campaign activity, theft and other charges against six former aides and supporters of Walker when he was the county executive of Milwaukee County.

Walker was not charged, but the governor spent an estimated $650,000 in campaign funds for defense attorneys during that investigation, which closed in March.

Capital W: Plug in to Wisconsin politics

Subscribe to our Politics email!

* I understand and agree that registration on or use of this site constitutes agreement to its user agreement and privacy policy.

Contact Dee J. Hall at dhall@madison.com or 608-252-6132. Contact Mary Spicuzza at mspicuzza@madison.com or 608-252-6122.