Wisconsin Gov. Scott Walker, who has had his eye on a 2016 presidential run since his battles with labor unions made him a Republican star, is dealing with the fallout of two criminal investigations at home that could complicate his move to the national stage.

One is ongoing, and although the other is closed and found no wrongdoing by Walker, it has the potential to embarrass him.

That was evident Wednesday with the release of more than 25,000 pages of e-mails from a former staff member that were gathered as part of the concluded inquiry.

The investigation focused on Walker’s time as Milwaukee county executive in the run-up to his 2010 election as governor and led to the convictions of six former aides and allies, including criminal convictions of two aides for performing political business on county time.

Prosecutors have said Walker was never a target, and he was not charged. Walker said Wednesday that the new disclosures revealed nothing beyond what authorities already had reviewed, and he predicted that Democrats would exaggerate their importance.

Search the documents Walker investigation files Newly released documents offer new clarity and prompt fresh questions about the extent to which the Wisconsin governor encouraged interaction between his 2010 campaign and his official aides.

The e-mails and other previously sealed court documents released Wednesday showed nearly daily coordination between Walker, his gubernatorial campaign and public employees in his county office.

Walker has characterized the activities as wayward behavior of low-level aides. But the e-mails show that he knew county officials were working closely with campaign officials.

Walker, for instance, directed his county staff members and campaign aides to hold a daily conference call to coordinate strategy, the documents show.

He routinely used a campaign e-mail account to communicate with county staff members, who also used private accounts, the documents show. Prosecutors have said the approach was used to shield political business from public scrutiny.

Wisconsin Gov. Scott Walker (R) told PostTV in January why he believes a governor should be the next president. (The Washington Post)

“Consider yourself now in the ‘inner circle,’ ” one county employee wrote to another in March 2010 after instructing her to check a non-public e-mail account frequently during the day. Referring to the future governor by his initials and his chief of staff, the employee continued, “I use this private account quite a bit to communicate with SKW and [Thomas] Nardelli.”

Walker told reporters Wednesday that he had not reviewed the documents but that he is “confident” that prosecutors had scrutinized them and decided they were not relevant.

“They chose to act on the ones that they’ve already made public,” he said. “I don’t know that there will be any great surprises beyond what they’ve already talked about.”

Walker said Democrats hoping to find damaging material are “going to be disappointed.”

“They’re going to do what they’ve done in the past, which is over-hype things,” he said.

Even if Walker emerges from the e-mail release unscathed, he faces an additional inquiry from state prosecutors, who are believed to be looking into whether his successful campaign in a 2012 recall election illegally coordinated with independent conservative groups that poured millions of dollars into Wisconsin.

That inquiry could create political challenges if it hobbles key campaign aides as Walker gears up for an expected vigorous reelection challenge in November.

Combined with the possibility of additional disclosures from the first investigation, the new inquiry threatens to hurt the governor as he attempts to gain momentum as a possible White House contender amid the scandal that has dimmed the 2016 prospects of a fellow star GOP governor, New Jersey’s Chris Christie.

Democrats sought Wednesday to use the e-mails as a chance to draw comparisons between Walker and Christie, who has said he was unaware of a plot by aides to create a massive traffic jam as a possible political retribution against a Democratic mayor. Christie’s troubles began with the release of internal e-mails.

“Scott Walker was absolutely aware that his staff was participating in illegal activity on the public’s dime,” said Mike Tate, Wisconsin’s Democratic Party chairman.

The Wisconsin investigations have been mysterious because of the state’s unusually strict secrecy laws, which have resulted in gag orders even for witnesses and targets. The rules have hampered Walker’s ability to respond and have left critics and allies alike uncertain about the extent to which the inquiries could damage him.

Some of the governor’s allies have criticized the investigations as politically biased, and one group, the Wisconsin Club for Growth, filed a federal lawsuit last week calling the probe into possible illegal coordination a violation of free-speech rights.

The e-mails released Wednesday come from the files of Kelly Rindfleisch, a former Walker deputy chief of staff who in 2012 pleaded guilty to a felony for ­performing political work for a ­Walker-backed candidate for lieutenant governor during hours she was being paid by taxpayers to do county business. The e-mails were unsealed as part of her appeal.

Some of the documents offered a rare glimpse into the inner workings of a politician’s office that was predictably hypersensitive to public perception.

In April 2010, Walker’s chief of staff informed him that officials with the Milwaukee County Behavioral Health Division were concerned because a Google search had revealed that a newly hired doctor had a history modeling thong underwear. “Apparently she’s competent, but even the Medical Director is dismayed that she has a varied lifestyle outside of her medical profession,” the chief of staff wrote.

Walker’s response came a few hours later: “Get rid of the MD asap.”

His allies said the reams of paper can’t reveal much new from a three-year investigation from which Walker emerged without serious political damage.

“The convictions they got were on the periphery and really had nothing to do with Scott Walker. It was collateral damage,” said Craig Peterson, a former Republican campaign strategist in Wisconsin. “What they wanted to find was corruption and they didn’t.”

In his book “Unintimidated,” released last year, Walker noted that efforts to use the inquiry against him in the 2012 recall campaign fell flat.

“I reminded the voters that as an Eagle Scout, ‘I live by the standards of integrity I got from my parents,’ ” he wrote.

Walker wrote that the investigation began after his chief of staff alerted the local district attorney to possible embezzlement at a veterans’ charity.

That sparked what is known as a “John Doe” investigation, a Wisconsin criminal tool that allows prosecutors to interview witnesses and subpoena records in front of a judge instead of a grand jury.

The investigation was broad.

Tim Russell, another Walker deputy chief of staff, was one of two people convicted of stealing from the veterans’ charity. Russell’s partner was found guilty of contributing to the delinquency of a minor. And a Walker campaign donor pleaded guilty to exceeding campaign finance limits by reimbursing employees of his railroad company for their donations.

“It was like a slow-moving glacier, picking up everything as it went,” said Michael Maistelman, a Democratic lawyer who for a time represented Russell.

Even in the face of profound pressure from prosecutors, Walker’s aides did not turn on him — and there is no sign that any are likely to provide new attention-grabbing information.

“I am certain that Kelly Rindfleisch isn’t going to be that person,” said Franklyn Gimbel, her attorney. “Under any circumstance, for any reason. Because she doesn’t believe he did anything.”

It is believed that some piece of evidence turned up that resulted in the opening of the ongoing second investigation.

The Milwaukee Journal Sentinel reported in October that the investigation is looking into possible illegal political coordination during the 2012 recall election and has spread to five Wisconsin counties, two of them with Republican district attorneys who have joined three Democratic prosecutors in turning over the case to a special prosecutor.

It is illegal in Wisconsin for candidates to coordinate campaign activities with outside groups that do not face the same restrictions on donations if the groups advocate for their election.

Democratic groups have long complained that the 2012 race was awash in outside spending, as conservative groups rallied to keep Walker in office. A Walker political adviser, they note, served as a spokesman to the Wisconsin Club for Growth, which spent heavily on the campaign.

Conservative groups have moved aggressively to try to convince federal and state judges, as well as the public, that the ongoing inquiry is an unfair partisan push meant to immobilize the right and hurt Walker.

A sealed judicial opinion issued this year and obtained by the Wall Street Journal’s conservative editorial page has fueled the effort. The document showed that a judge quashed a set of subpoenas in the inquiry, ruling that prosecutors had failed “to show probable cause that a crime was committed.”

The newspaper editorial said the ruling vindicated the suspicion that the “probe is a political operation intended to shut up Mr. Walker’s allies as he seeks re-election this year.” Prosecutors are likely to appeal the ruling.

In its lawsuit, the Wisconsin Club for Growth, one of 29 right-leaning groups that have received subpoenas in the matter, charged that the still-secret inquiry is “calculated to chill protected speech.”

David Rivkin, a Washington-based attorney for the Club for Growth, said that already, the investigation has largely halted the group’s political activities in the state.

He said the probe has sidelined the anti-tax group from weighing in on behalf of a $500 million tax cut Walker is advocating, while the secrecy rules inhibit its ability to fully defend itself. Even the group’s federal complaint is heavily redacted in deference to the John Doe rules.

The lawsuit also accuses Milwaukee District Attorney John Chisholm, a Democrat who began both investigations, of political bias. It notes, for instance, that there has been no indication that any left-leaning groups have faced similar scrutiny though unions were active in the election as well.

If conservative groups succeed in undermining the investigation’s legitimacy, the result could convert the inquiry from a possible Walker weakness into an un­expected strength, rallying conservatives around a governor perceived to be holding firm against liberal bullies.

Sean Sullivan and Matt DeLong contributed to this report.