Democrats in the US House of Representatives have called for the immediate suspension of as they launch an investigation into his testimony to lawmakers, the Washington Post newspaper said on Monday.
The paper quoted Carolyn Maloney, the Democratic chairwoman of the Oversight and Reform Committee, as saying the committee would start an investigation, adding that DeJoy may have lied to it under oath.
The move follows accusations that DeJoy reimbursed former employees for campaign contributions to his preferred Republican politicians, an arrangement that would be illegal.
Maloney's office did not immediately respond to a request for comment.
Earlier on Monday, US President Donald Trump said he would support an investigation into campaign contributions involving DeJoy.
Last week, DeJoy received a subpoena from the congressional panel seeking documents connected to his decision to implement changes that Democrats said threatened mail deliveries and the 2020 election.
Senate Democratic leader Chuck Schumer called on Sunday for the North Carolina attorney general to investigate allegations published in the Washington Post that DeJoy's former company reimbursed employees for political donations.
DeJoy, a donor to Trump, has been in the political spotlight after ordering operational changes and a clampdown on overtime at the US Postal Service.
Democrats have accused him of deliberately disrupting the Postal Service just as millions of Americans consider whether to cast their ballots by mail in the November 3 presidential election.