Indicted Ald. Edward Burke (14th) had a series of so-called burner cellphones, at least one of which was bought by an underling who paid cash for the device months before the federal raid on Burke’s ward and City Hall offices, the Chicago Sun-Times has learned.

Federal authorities only learned about that phone recently, sources familiar with the investigation said. Its existence raises the possibility that the alderman may have been alerted to, or was suspicious of, the investigation that led to the criminal case that was filed against him earlier this year.

A court-approved FBI wiretap of Burke’s main cellphone recorded more than 62,000 calls the alderman made or received over several months, records have shown. That includes recordings that formed the basis of the Jan. 3 charge of attempted extortion against Burke for allegedly shaking down a Burger King franchise owner for legal business.

In one call, Burke was overheard plotting with indicted top aide Peter Andrews on how to play “hardball” by holding up permits and papering the Burger King with bogus citations until the franchise owner hired Burke’s law firm, Klafter & Burke, to handle its property tax appeals.

But, what the feds did not know — at least until recently — was that Burke had at least one other pay-as-you-go “burner” phone that he asked the underling to buy for him last summer. There was no wiretap on that phone and no city record of the cash purchase, sources said.

That phone was among a series of Burke burner phones normally purchased by customers who don’t want to pay a monthly bill.

Criminals have been known to buy such pay-as-you-go phones so they can conduct illegal transactions and dump the devices.

Burke, who has denied any wrongdoing, could not be reached for comment. His criminal defense attorney Chuck Sklarsky refused to comment. So did the U.S. Attorney’s office.

The Sun-Times is not identifying the longtime Burke employee who purchased the burner phone last summer because that person has not been charged with any wrongdoing.

Sources said the employee was recently questioned by the feds. The employee initially neglected to tell them about the burner phone, only to return for a second round of questioning and provide the information.

Contacted Wednesday, the employee refused to discuss the burner phone and hung up on a reporter.

“I don’t have any comment about this,” the employee said, refusing to say whether he had been questioned by federal investigators. “I’m going to have to go now. I’m on the clock.”

Ald. Scott Waguespack (32nd), who replaced Burke as Finance Committee chairman, said he knew nothing about the phone, but he knows of the Burke employee with whom the Sun-Times spoke.

The employee is a technology whiz who was involved with Burke’s iron-fisted oversight over Chicago’s $100 million-a-year workers’ compensation program before it was transferred from the Finance Committee to the city’s Department of Finance after Burke was charged. Mayor Lori Lightfoot has since hired a claims administrator to ride herd over the program she claims was so loosely run, it was “ripe for corruption.”

On Wednesday, Waguespack disclosed that the Finance Committee he inherited had its own email server — and that Burke had a surveillance camera system and a series of safe deposit boxes all apparently tied to workers’ comp.

“My understanding was that a [disgruntled] city worker had accosted a woman up front and they put in a camera system to basically keep track of anybody else or if that person came back up. The person was angry about their workers comp claim,” Waguespack said.

Waguespack said that, so far as he can tell, there was nothing nefarious about the safe deposit boxes. But, he added, “I don’t have access to it any more. We sent everything over to the Finance Department. Either the IG [Inspector General], the Law Department and the Finance Department have all the files now. I transferred everything over to them.”

On Nov. 29, federal investigators raided Burke’s ward and City Hall offices, covering the glass doors with brown butcher paper.

On Jan. 3, Burke was hit with the attempted extortion charge, which he shook off on his way to re-election.

On May 30, Burke was charged in a 14-count indictment based on a federal racketeering statute.

The indictment includes the alleged Burger King shakedown and three similar schemes, including one chronicled by former Zoning Committee Chairman Danny Solis (25th), who spent two years wearing a wire to help the feds build their corruption case against Burke.

Among the other alleged schemes are that Burke tried to extort legal business from 601W Companies, developers of the Old Main Post Office, in exchange for Burke’s help with a variety of matters.

In those recordings, an irritated Burke was caught on tape asking Solis, “Did we land the, uh, tuna?” and complaining that the “cash register has not rung yet” and, until he scored the legal business, he was not “motivated” to help the developer with its issues at the Post Office. “As far as I’m concerned, they can go f--- themselves,” Burke said.