The internal investigator for Chicago Public Schools questioned CPS CEO Forrest Claypool at the school system’s main offices on Thursday, the Chicago Sun-Times has learned.

Inspector General Nicholas Schuler spoke with Claypool about a contract between the Chicago Board of Education and the law firm that’s paying a seven-figure severance to the school system’s general counsel.

In a confidential report to school board members in June, Schuler had written that the general counsel, Ronald Marmer, violated the school system’s ethics code by supervising $182,000 in work that a previous employer, Jenner & Block LLP, did for the schools while simultaneously paying him a severance package.

Schuler’s report, which the Sun-Times has reviewed, alleged that Claypool was involved in an “apparent whitewash attempt” of Marmer’s violation.

Schuler said six lawyers — four at CPS and two from outside firms — privately advised school officials that Marmer was violating the ethics code. Only after CPS went to a seventh lawyer, in June 2016, did Claypool secure a legal opinion defending Marmer’s conduct.

That seventh opinion came from J. Timothy Eaton — a lawyer who has contributed to Claypool’s political campaigns.

“The clear inference is that Claypool had to shop through six lawyers until he found a seventh one who would publicly clear Marmer,” Schuler wrote.

The inspector general also wrote that administrators and Eaton have obstructed his office’s investigation “into the apparent whitewashing of Marmer’s ethical violations.”

For months, CPS leaders blocked Schuler from completing his investigation into the matter, claiming that the lawyers involved did not have to speak to the inspector general’s office.

Then, in September, schools officials disclosed that they would “fully cooperate” with the probe.

Asked Friday about Schuler questioning Claypool, CPS spokeswoman Emily Bittner said: “CPS continues to cooperate in this matter concerning a dispute between attorneys over an interpretation of a board policy.”

Schuler did not return calls seeking comment.

Schuler’s investigation into Marmer’s dealings with Jenner & Block began 15 months ago, shortly after the Sun-Times reported that Jenner & Block was paying Marmer a $1 million severance in five annual installments of $200,000, with the final check scheduled for next year.

At the time, Claypool said Marmer had nothing to do with hiring Jenner & Block to work for CPS on a lawsuit against the state for increased funding.

But the CPS ethics code prohibits administrators from supervising the work of contractors with whom they have a business relationship — defined as a transaction worth at least $2,500 in a calendar year to an official.

“Ronald Marmer violated the code of ethics by exercising ‘contract management authority’ over legal work performed by his former employer Jenner & Block because he clearly has an ongoing ‘business relationship’ as defined by the code,” Schuler wrote in June.

He also wrote that his office “is investigating what appears to be an attempt by Claypool, and possibly others, to paper over the opinions of the six attorneys with Eaton’s letter.”

In December, Schuler had taken the unusual step of appearing at a school board meeting to complain publicly that officials were stonewalling his office’s investigation into Marmer.

Schuler’s update to the board in June was a preliminary report. Now that CPS has stopped stonewalling the investigation, the I.G.’s office could complete the probe and issue a final report.

Under the ethics code, violators could face suspension or firing.

State election records show Eaton contributed $5,000 to Claypool’s campaigns. Eaton is a partner at the Taft Stettinius & Hollister LLP firm.

CPS paid the firm $1,475 for Eaton’s letter defending Marmer, which took him five hours in June 2016 to prepare, according to district records.

Marmer left Jenner & Block in 2013 and joined CPS in 2015. He’s paid $185,000 a year.