(CNN) Donald Trump's fresh acknowledgment this week that he reimbursed his lawyer Michael Cohen more than $100,000 in 2017 is raising red flags with ethics experts about why the President withheld information from the public about those payments last year.
Trump's financial disclosure report released on Wednesday -- covering all of 2017-- stated the President paid Cohen back last year between $100,001 and $250,000 for various expenses Cohen incurred while working for Trump.
"Mr. Cohen sought reimbursement of those expenses and Mr. Trump fully reimbursed Mr. Cohen in 2017," the disclosure said.
While Wednesday's disclosure did not specify what Cohen was being reimbursed for, he paid porn star Stormy Daniels $130,000 in October 2016 as a part of a hush agreement to keep the porn star quiet about her alleged affair with Trump.
That revelation has brought to stark focus the reality that Trump's previous financial disclosure report released last June -- which covered all of 2016 through mid-April 2017 -- made no mention of Trump's payments to Cohen, despite the fact that Rudy Giuliani, Trump's lawyer, recently said that Trump's monthly payments to Cohen began in early 2017.
"Some time after the campaign is over, they set up a reimbursement, $35,000 a month, out of his personal family account," Giuliani told The New York Times. In total, Trump paid Cohen $460,000 or $470,000 to include money for "incidental expenses," he added.
It was not immediately clear why Giuliani referred to a significantly higher figure than the range that was disclosed this week.
Trump's critics and government transparency advocates, including Citizens for Responsibility and Ethics Executive Director Noah Bookbinder, say the Justice Department must investigate whether the failure to disclose the debt last year was "knowing and willful, in which case it would have been a federal crime."
"The Office of Government Ethics has now determined that the President's debt to Michael Cohen needs to be reported on his financial disclosure report, rejecting the President's claim that it does not," Bookbinder told CNN. "Because this was a debt incurred in 2016 and repaid starting in early 2017, it clearly should have been included on the President's 2017 report, which covered any debts through May 2017."
Trump's explanation for why the Cohen payments were not included in last year's report was clear in the President's disclosure this week: He simply did not believe the reimbursement to Cohen was "required to be disclosed as a 'reportable liabilities.'"
The reason Trump nevertheless included mention of the Cohen payments in his disclosure this week, the report said, was "in the interest of transparency."
White House press secretary Sarah Sanders would not elaborate on the statement Thursday when pressed by reporters.
"That was addressed in the financial disclosure. That is something that would be determined by White House counsel," Sanders said.
But the Office of Government Ethics was unequivocal in its own conclusion, disagreeing with the President.
"The information related to the payment made by Mr. Cohen is required to be reported and that the information provided meets the disclosure requirement for a reportable liability," it said.
In addition to including a statement on Trump's financial disclosure, the OGE's acting director David Apol sent a letter to the Justice Department, noting that Trump should have disclosed the payment under the law.
The office did not, however, specify what year the disclosure should have taken place or indicate whether it believed Trump violated the law.
Former OGE director and CNN contributor Walter Shaub said the letter to the Justice Department raised eyebrows.
"Apol's decision to release his referral letter was actually quite aggressive," Shaub said. "His letter is as formal as anything OGE has ever sent DOJ. Most OGE referrals are just informal calls or emails."
The Justice Department declined to comment on the letter.
Cohen has previously said that he used his personal funds to make the payment, and that the Trump Organization and Trump campaign were not involved in the agreement and neither reimbursed him for the $130,000.