WASHINGTON (Reuters) - President-elect Donald Trump on Wednesday backed a call for the FBI to investigate fellow Republican former congresswoman Liz Cheney over her role in leading Congress's probe of the Jan. 6, 2021, assault on the U.S. Capitol by his supporters.

Trump, who will return to the White House on Jan. 20, has vowed retribution against his rivals, including the prosecutors who brought criminal cases against him while he was out of power, and former officials he contends impeded him during his 2017-2021 term.

He has also said he may grant clemency to some of the more than 1,250 people criminally charged for their role in the Jan. 6 attack, which was an attempt to overturn Trump's 2020 election defeat. More than 140 police officers were injured in the violence, five people including a police officer died during or shortly after the riot and the Capitol sustained more than $2.8 million in damage.

"Liz Cheney could be in a lot of trouble based on the evidence obtained by the subcommittee, which states that 'numerous federal laws were likely broken by Liz Cheney, and these violations should be investigated by the FBI,'" Trump wrote in an early morning post on his Truth Social site.

His post referred to the Tuesday release of a report by the Republican-led House Administration Oversight Committee, which called for a probe of Cheney, the daughter of Republican former Vice President Dick Cheney, who lost her re-election bid in 2022.

Cheney in a statement alleged that the report amounted to an attempt to whitewash Trump's role in the events of Jan. 6.

"Their allegations do not reflect a review of the actual evidence and are a malicious and cowardly assault on the truth," Cheney said in a social media post on Bluesky. "No reputable lawyer, legislator or judge would take this seriously."

(Reporting by Doina Chiacu; Editing by Scott Malone and Chizu Nomiyama)