The House Ethics Committee launched a formal investigation into allegations that senior Democratic lawmaker Rep. John Conyers Jr. (Mich.) sexually harassed female aides and used office funds to settle a former staffer's claim that she was fired after rejecting his advances.

Ethics Chairwoman Susan Brooks (R-Ind.) and ranking Democrat Ted Deutch (D-Fla.) announced the start of a probe into Conyers, 88, the longest-serving member of the House and top Democrat on the powerful Judiciary Committee.

"The Committee is aware of public allegations that Representative John Conyers Jr. may have engaged in sexual harassment of members of his staff, discriminated against certain staff on the basis of age, and used official resources for impermissible personal purposes," Brooks and Deutch said in a statement.

Shortly after the probe was announced, BuzzFeed News reported a second allegation by a former Conyers aide, who claimed in court filings this year that he sexually harassed her. BuzzFeed reported the 2015 settlement between Conyers and an unnamed former employee late Monday.

On Tuesday, Conyers initially denied that he had settled sexual harassment claims when asked by an Associated Press reporter at his Detroit home. Later in the day, he reversed himself and acknowledged the settlement while emphasizing that he never admitted fault.

Conyers said he would cooperate with a House investigation into the matter.

"I expressly and vehemently denied the allegations made against me, and continue to do so," Conyers said in a written statement.

"My office resolved the allegations — with an express denial of liability — to save all involved from the rigors of protracted litigation. That should not be lost in the narrative," he stated.

Conyers's spokeswoman, Shadawn Reddick-Smith, said Conyers originally denied the existence of a settlement because he was "under the impression the reporter was speaking of recent allegations of which he was unaware."

Conyers is the ranking Democrat on the House Judiciary Committee, and House Minority Leader Nancy Pelosi (D-Calif.), in a statement Tuesday, did not address whether she would ask Conyers to resign.

"As Members of Congress, we each have a responsibility to uphold the integrity of the House of Representatives and to ensure a climate of dignity and respect, with zero tolerance for harassment, discrimination, bullying or abuse. As I have said before, any credible allegation of sexual harassment must be investigated by the Ethics Committee," Pelosi said.

Pelosi, House Democratic Whip Steny H. Hoyer (Md.) and House Democratic Caucus Chairman Joe Crowley (N.Y.) urged the House to overhaul the process for reporting and resolving workplace violations with changes proposed by Rep. Jackie Speier (D-Calif.). Hoyer also called for the Committee on Administration to establish "new rules to protect victims."

Conyers paid his former employee more than $27,000 from office funds after she made the harassment accusation, listing the payments as employee severance, according to House payroll records compiled by LegiStorm, a subscription-based data source.

"The resolution was not for millions of dollars, but rather for an amount that equated to a reasonable severance payment. There are statutory requirements of confidentiality that apply to both the employee and me regarding this matter," Conyers said Tuesday.

Using office funds to settle a claim may call into question the accuracy of a settlement number released earlier by the nonpartisan Office of Compliance. The office, which is charged with adjudicating workplace claims on Capitol Hill, recently said the government has paid more than $17 million to settle alleged rule violations in the past 20 years; however, that estimate did not account for payments made directly from members' office budgets.

"Beyond the sexual harassment allegations are allegations that call into question the amount of money that is used to settle sexual harassment cases, and whether some Members are using their tax payer-funded office budgets to make settlements under the guise of severance payments," Speier said in a statement.

"If this is true, the amount of taxpayer money used to settle these cases is even higher than the number that's been provided by the Office of Compliance," she said.

The House last week said it would require members and aides to undergo anti-harassment training for the first time. But leaders have declined to take further concrete steps to address cascading allegations of sexual harassment in House offices.

Speaker Paul D. Ryan (R-Wis.), calling the original BuzzFeed report "extremely troubling," noted that the House Administration Committee is reviewing congressional workplace policies with the goal of making changes that will curb harassment.

"Additional reforms to the system are under consideration as the committee continues its review," Ryan said in a statement Tuesday. "People who work in the House deserve and are entitled to a workplace without harassment or discrimination."

On the Senate side, Judiciary Committee Chairman Charles E. Grassley (R-Iowa) indicated he was looking into how he might change the Congressional Accountability Act, a 1995 law he wrote that established the t procedures for reporting harassment, to make it friendlier to victims.

"As author of underlying legislation I must look at the regulations on investigating sex harass complaints that favor the aggressors," Grassley tweeted.