The House ethics committee on Tuesday opened a formal probe into longtime Michigan Democratic Rep. John Conyers over reports he sexually harassed staff and quietly settled allegations with taxpayer money.

In a statement announcing the investigation, the bipartisan committee said it is aware of allegations that Conyers “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.”

Conyers, 88, “expressly and vehemently” denied the charges of sexual misconduct lodged by his staff members.

Conyers’ office reportedly paid the woman over $27,000 to settle the complaint under a confidentiality agreement, BuzzFeed News reported.

The website later reported that another former staffer alleged that she endured sexual harassment by the congressman, according to court documents.

The former scheduler in Conyers’ office attempted to file a sealed lawsuit against him this February in federal court in Washington that alleges she suffered unwanted touching by the Democrat “repeatedly and daily.”

She abandoned the lawsuit the next month, after the court denied her motion to seal the complaint.

In court documents, the scheduler said she had a “fatherly affection” for the “Civil Rights icon” Conyers.

The woman was hired, in part, to keep an eye on Conyers due to his “age and failing mental capacities,” the lawsuit said, according to BuzzFeed.

She claimed that part of her job included delivering medication to him every day and calling to wake him up.

Conyers’ daily advances became so bad, the woman said in court papers, that she asked a male staffer to pretend to be her boyfriend in hopes of cooling off the lawmaker.

House Speaker Paul Ryan says it was “deeply troubling” that the Michigan lawmaker settled the complaint, and that the House is changing its procedures for handling charges of harassment and discrimination, which have been called too weak and cumbersome.

Rep. Jackie Speier (D-Calif.), who has authored legislation to revamp sexual harassment reporting in Congress, said the case raises new concerns about the magnitude of the problem.

The Office of Compliance has records of 264 settlements since 1997 of workplace disputes – including sexual misconduct – worth more than $17 million. But since Conyers used his taxpayer funded office budget to settle, it would not be in the tally.

“If this is true, the amount of taxpayer money used to settle these cases is even higher than the number that’s been provided,” Speier said.

A former member of Conyers staff said the congressman has a long history of inappropriately touching of subordinates, asking staff to handle his personal affairs and wanting to “dispose” of female staffers as they got “too old.”

The staffer, speaking to the Post anonymously, said he provided an affidavit in the settlement case in support of the woman. He reported Conyers rubbed the woman’s hands and her legs and left her inappropriate voice mails.

The former aide said he confronted Conyers when a volunteer driver also reported Conyers also rubbed her legs.

“I told him it was inappropriate,” the staffer said. “You can’t do that, congressman. I counseled him at least two or three times on it. … He said he’d work on it.”

A current member of congress said Conyers’ misdeeds with staffers have long been rumored and the allegations exposed this week are not a surprise. “It’s where it needs to be – ethics,” the relieved House member told The Post.

However, a defiant Conyers said in a statement “the mere making of an allegation does not mean it is true.”

He said he “resolved the allegations — with an express denial of liability — in order to save all involved from the rigors of protracted litigation.”

“The resolution was not for millions of dollars, but rather for an amount that equated to a reasonable severance payment.”

Conyers is no stranger to Ethics Committee investigations. In 2006, the bipartisan panel said Conyers agreed to make changes after his congressional staffers complained the civil rights leader had them babysit his kids, run personal errands and work on political campaigns.

In 2010, Conyers reimbursed $5,682 to the US Treasury when his son was caught driving the taxpayer-funded Cadillac Escalade after he reported two laptops and $27,000 in concert tickets were stolen from the SUV.

Last year, Conyers’ former chief of staff, Cynthia Martin, pleaded guilty to receiving stolen property after initially refusing to return $16,500 mistakenly transferred to her bank account.

Investigators believed Conyers continued to pay Martin when no she longer worked for the House.

The Ethics Committee has launched a review.

Conyers, 88, is married to Monica Conyers, 52, a former Detroit City Councilwoman who served time in federal prison in a City Hall bribery case.