Retiring Ald. Danny Solis (25th), the powerful chairman of the City Council’s Zoning Committee, has secretly recorded more than a dozen conversations with Ald. Ed Burke (14th) over the last two years, including at City Hall, to help federal investigators build their corruption case against him, the Chicago Sun-Times has learned.

Those conversations include Burke meeting with individuals seeking actions by the city, a source familiar with the matter said.

Federal investigators have focused on Burke allegedly using his influence as chairman of the City Council’s Finance Committee to drum up property tax appeal business for his private law firm.

Some of the meetings Solis recorded using an electronic listening device took place at the suite of offices reserved for the Finance Committee chairman on the third floor of City Hall.

That’s the same suite that federal investigators raided Nov. 29, covering the glass doors with brown butcher paper to conceal the search inside.

Other meetings allegedly took place at Burke’s ward office, the source said. The FBI searched that office the same day as the City Hall raid.

Burke, the City Council’s longest-serving alderman, has been charged with one count of attempted extortion for allegedly shaking down a Burger King franchise owner for legal business at the same time the company needed permits for work on a restaurant in his ward.

He is also accused of shaking down the same businessman for a $10,000 campaign contribution for County Board President Toni Preckwinkle. Preckwinkle’s campaign returned the donation, which exceeded the legal limits, and has said it knew nothing about what prompted the donation.

Solis’ cooperation is extraordinary, not only because the target was Burke but because Solis was a trusted ally of both Burke and Mayor Rahm Emanuel. Solis’ position as Zoning Committee chairman gave him the influence and standing to arrange for meetings where Burke could pitch potential clients.

In late November, Solis surprised his colleagues by announcing that he would not seek re-election, ending a 23-year career in the City Council that began with his 1996 appointment by then-Mayor Richard M. Daley to replace the disgraced and convicted Ambrosio Medrano.

Now that his role as an FBI mole has been exposed, Solis is prepared to resign immediately and start taking his aldermanic pension, the source said.

Solis has not been charged with any wrongdoing, and it’s unclear if he will be facing any charges.

Solis has previously denied being an informant or wearing a recording device for the feds. He did not return a phone message this week seeking comment on the Sun-Times story.

A spokesman for Burke did not return a message for comment, but the alderman has denied any wrongdoing.

A spokesman for the U.S. attorney’s office in Chicago had no comment.

Well aware that rumors were flying around political circles about the undercover role that he played in the Burke scandal, Solis arranged for a college visit with his son this week, which is giving him an excuse not to attend Wednesday’s City Council meeting, the source said.

Solis is not likely to attend another City Council meeting as 25th Ward alderman. Nor is he likely to be honored with the fawning City Council resolution — complete with laudatory speeches by his colleagues — that almost always accompanies an aldermanic retirement.

Days after announcing his own retirement, Solis appeared on the WTTW-TV program, “Chicago Tonight,” to discuss his decision to walk away.

During that interview, he made an extraordinary statement.

“I think Ald. Burke should reconsider [re-election],” Solis said then.

“You got money, you got a great family, you got grandkids. Why do you want to run?”

Now, a remark that appeared to be a verbal knife in the back to a longtime colleague starts to make sense, given Solis’ role in the Burke case.

Over the years, City Hall has been hit with a steady stream of corruption scandals involving undercover FBI moles.

They have included corrupt businessmen John Christopher, the star witness of Operation Silver Shovel, and Michael Raymond, who played a central role in the corruption scandal known as Operation Incubator.

What is far more unusual is to have a sitting alderman agree to use a recording device to help snare a colleague.

Typically, elected officials agree to go undercover, only after they themselves have been caught in corruption scandals.

That was the case with former Ald. Allan Streeter (17th), who wore a wire during the early 1980s and is believed to be the last sitting Chicago alderman to work as an undercover FBI mole.

In 1996, Medrano (25th) was a crooked alderman hailed as a hero by some for refusing to do something his colleagues considered even worse.

After getting caught up in the federal corruption probe known as Operation Silver Shovel — and accepting $31,000 in bribes from Christopher, a convicted felon and waste hauler who turned into an FBI informant — Medrano was asked to wear a wire to snare other corrupt politicians but he refused.

A veteran Hispanic aldermen, Medrano was hailed as a stand-up guy, in contrast to Streeter, who was branded a “rat” for doing what Medrano had refused to do.

“I grew up in a neighborhood where people respect certain things, and one of the things that they respect is that, if you get in trouble, you don’t squeal. You take it like a man,” Medrano said at the time.

“I’m not a snitch. It’s just something that I don’t do. My problems have nothing to do with other people’s problems. Nothing. Not that anybody did anything wrong. Not that I knew that anybody did anything wrong. I didn’t want to even give that impression.”

In addition to the chilling impact on Solis’ City Council colleagues, his undercover role in the Burke investigation could also rock the crowded race for mayor.

Patti Solis Doyle, the alderman’s sister and a former adviser to the presidential campaigns of Barack Obama and Hillary Clinton, is scheduled to host a Jan. 29 fundraiser in Washington, D.C., for State Comptroller Susana Mendoza, who is among the frontrunners in the Chicago mayoral race.

It’s unclear whether Mendoza will proceed with those plans. Mendoza considers Burke a political mentor. She would not have been elected as a state representative without his help. She was also married at the alderman’s home.

Like the rest of the mayoral field, Mendoza has tried to distance herself from Burke since the alderman was charged. She has donated the money he gave her to the families of deceased Chicago Police officers.

Contributing: Tim Novak