Metro’s ethics investigation of board chairman Jack Evans has grown so surreal that D.C. Mayor Muriel E. Bowser was demanding Tuesday to see the full legal report on the probe, which board members say does not exist, and Maryland Gov. Larry Hogan was talking about a “coverup.”

That’s the kind of problem that arises when an oversight body — in this case, the Metro board’s ethics committee — meets in secret with no written record of its proceedings, and its members can’t agree on what they decided.

It would be laughable if the stakes weren’t so high. The scandal already is pitting Hogan (R), an outspoken Evans critic, against Bowser (D), who is defending him. The dispute threatens the regional cooperation that resulted in last year’s historic dedicated-funding agreement for the transit agency.

The controversy also is raising the most significant concerns in recent memory about possible corruption and dishonesty at the top at Metro. Evans said Tuesday that the ethics committee found no violations on his part — but three of the committee’s four members said it reached a majority consensus on one. The committee’s chairman, Clarence W. Crawford, said the reason it was not put in writing was because Evans and his lawyer said it would not be necessary.

Taken together, it is the latest sign that Metro needs improved governance and more transparency and accountability, as critics have been saying for years.

The law firm Schulte Roth & Zabel, hired by Metro in March to investigate potential conflicts of interest for Evans, delivered a blockbuster finding, according to Crawford.

The firm found “multiple violations” of the board’s ethics code. It found 16 separate ways in which Evans violated either the ethics code or the Metro Compact, in particular his being paid $50,000 a year by Colonial Parking while using his Metro position to try to hurt a Colonial competitor, LAZ Parking.

Metro Inspector General Geoff Cherrington confirmed Tuesday that Evans twice asked him to reopen a closed inquiry into LAZ. Cherrington looked into it, but he chose not to launch a new full-scale investigation.

It is of grave public concern that a figure as powerful as Evans is facing such a scandal. For more than three years, he has headed the board overseeing the region’s core transit network, a multibillion-dollar enterprise.

Yet the public would not have learned about these allegations if not for Hogan and Virginia Gov. Ralph Northam (D), who on Monday wrote to the ethics committee demanding that it disclose the results of its six-week probe.

Crawford, who had said in May that the investigation was closed and the results would not be released, relented within hours of the governors’ letter, providing a four-page summary of the findings.

The fiasco is not over. Hogan demanded Tuesday that all results, not just a summary, of the investigation be released, and he reiterated his call for Evans to resign from the Metro board.

“Jack Evans’s corruption has forced [the Washington Metropolitan Area Transit Authority] to go to great lengths to cover up his extensive wrongdoing,” Hogan tweeted. “This is outrageous and totally unacceptable. Maryland funds WMATA, and we deserve to know everything this investigation uncovered — no sugarcoating or stonewalling.”

Bowser and D.C. Council Chairman Phil Mendelson (D) also said they wanted to see the law firm’s full report.

But there is no such report, according to committee members. Instead, there are memos that Schulte Roth & Zabel used to prepare an oral presentation to the committee, and supporting documents from the firm’s investigation.

There is no formal report because the four-member ethics committee avoided putting anything in writing.

“That was the agreement that we had at the committee, that there’s no written report that would be given to us,” said ethics committee member Corbett Price, who represents the District on the Metro board and usually is allied with Evans.

The decision was taken on the recommendations of lawyers, who warned that such a report could be used in the future to support a lawsuit against Metro, officials said. It was not clear whether the advice came from outside counsel, Metro’s corporate counsel or both.

In addition, no written minutes were taken at the ethics committee meetings. That has contributed to the dispute over whether the committee found that Evans had committed any violations at all.

There is also a disagreement over whether Evans’s announcement that he would not seek reelection as board chair when his term ends June 30 was part of the agreement that led to the investigation being closed.

Crawford’s letter to the governors said that a majority of the committee reached agreement that Evans had committed a single ethics violation, regarding a conflict of interest in his dealings with Colonial Parking. Ethics committee member David Horner, who represents the federal government, said the same on Monday. Crawford and Horner also said the deal included the commitment that Evans would not seek reelection as chair.

On Tuesday, a third committee member, Paul Smedberg, who represents Virginia, agreed on both points.

But Evans and Price say neither of those things happened. Evans told WAMU-FM 88.5 on Tuesday that “the ethics committee at Metro found no violation of any ethics rules on my part.” Evans has said previously he planned for months not to seek reelection.

Evans later refused to speak to a Washington Post reporter at the John A. Wilson Building, and his spokesman declined to answer questions about the investigation.

Crawford said the committee agreed on its findings at a May 7 meeting.

“At the end of the meeting, I asked that this be put in writing, but Jack and his attorneys said, ‘That’s not necessary,’ ” Crawford said Tuesday. To ensure everyone had the same understanding of what was agreed to, Crawford said he went over the details four times in 90 minutes of conversation with Evans and his attorney, Mark Tuohey.

Tuohey said other committee members agreed that the findings did not need to be put in writing. Evans’s position is that if the committee had found an ethics violation, it would have been required to report the violation to the full board, which it did not.

Crawford and Horner said they were dissatisfied with Metro’s established procedures in conducting the investigation. Horner faulted the lack of a written record and what he said were unclear standards for evaluating wrongdoing.

“Members of the ethics committee had to contend with a shambolic process not of our own making,” Horner said. “Reform of [Metro] governance is not finished.”

Crawford said Metro should revise its rules so any ethics investigation is required to end with a written report.

Bowser took Evans’s side in the dispute over whether the ethics committee found he had committed a violation.

“They, I believe, didn’t find the evidence was persuasive that there were violations to Metro’s ethics code,” she told reporters.

“I would be concerned about any conflicts of interests, but I’m also concerned about the Metro process not being transparent,” she said.

Mendelson said Tuesday that he had only “glanced” at the letter summarizing the ethics investigation, but he said he had “a number of questions” and called on the Metro board to release the full investigation.

Asked whether Evans should continue to represent the District on the Metro board, Mendelson said he would need to see the full investigation first. “It’s too soon for me to answer that,” he said.

Peter Jamison, Fenit Nirappil and Steve Thompson contributed to this report.