A Minnesota retirement system for public school teachers under Gov. Tim Walz  is “cooking the books” by vastly underreporting annual fees paid to Wall Street investment managers — and posting near-impossible gains tantamount to a “Madoff miracle,” a top pension investigator said.

The state-run Teachers Retirement Association, or TRA, has publicly disclosed less than 10% of an estimated $2.9 billion spent on fees in the past 10 years, said Edward Siedle, a former Security and Exchange Commission lawyer and independent pension investigator. 

The TRA also posted gains claiming it beat its own custom benchmark over periods of one, five, 10, 20 and 30 years by exactly 0.2%, which Siedle called “virtually impossible.”

The findings raise questions whether the fund is concealing mismanagement, and ultimately whether there is enough money to pay retirees their promised benefits, Siedle told The Post.. 

“Even Bernie Madoff didn’t claim to beat the market every single year — and certainly not by the exact same percentage,” said the investigator, calling the TRA’s purported performance a  “Madoff miracle under Walz’s watch.”

The findings also raise questions about Walz’s leadership now that he’s Kamala Harris’ running mate on the Democratic presidential ticket, Siedle added.

“I don’t know if the man had any pre-existing knowledge of finance or pensions, but as chairman he should have educated himself,” Siedle said. “Pension board members have a fiduciary duty to monitor fees, and to ensure that the investments’ performance is accurately disclosed.”

A Minnesota teachers’ advocacy group concerned about a lack of transparency raised $78,373 on GoFundMe to hire Siedle to conduct a forensic audit of the TRA, which manages pensions for 215,000 active and retired educators. Contributions come from taxpayer dollars as well as mandatory salary deductions. 

The group, Minnesota Public Educators for Pension Reform, has complained of “inequities,” including “significantly decreased benefits” for some members. 

Katie Dickerson, a 55-year-old teacher, testified in February to Minnesota’s Legislative Commission on Pensions and Retirement, “As I am getting closer to retirement, I realize the state never made improvements to our retirement system. Not only do we have a high contribution rate to TRA, but we …are forced to work many more years unless we are willing to be hit with huge penalties.”

The reform group accused the TRA of “presenting the public with misinformation.”

“We have lost trust in a system that was allegedly tasked with protecting our retirement security,” the group said in a statement.

Since starting his term in January 2019, Walz has served as chairman of the Minnesota State Retirement System, which manages $140 billion in funds for all state employees, including $28.2 billion for teachers.

According to TRA’s financial statements for FY 2023, the fund produced an 8.9% rate of return.

The TRA reported $24.19 million in management fees in 2023. But Siedle estimated the total paid to Wall Street fund managers ranged from $334 million to $467 million, or 5% to 7% of the TRA’s private assets. Even if the fees were only 1%, they would total $280 million — more than 10 times the disclosed fees.

As part of his probe, Siedle filed public-records requests with the TRA and the state for investment documents, but the agencies have not yet complied, he said.

In his report, Siedle says the Minnesota attorney general and state auditors would normally investigate irregularities, but those officials sit on the same state pension board that Walz chairs. As a result, Siedle filed a whistleblower complaint with the SEC and the FBI last month. 

South Carolina state treasurer Curtis Loftis, who wrote a forward to Siedle’s book, “How to Steal A Lot of Money — Legally,” told The Post he supports the probe.

“Pension plan leaders often seem disconnected from the working men and women they represent, preferring to prioritize the concerns of Wall Street investment managers and high-ranking government officials over policemen, teachers and firemen,” Loftis said.

Walz and Harris have trumpeted the governor’s history as a 20-year social studies teacher. 

“Don’t underestimate teachers,” he warned Tuesday in his first speech as a vice-presidential candidate.

Walz and TRA officials did not return messages.