Ex-FBI director James Comey has been charged with making a false statement and obstruction in a criminal case.
Comey was fired months into Donald Trump's first presidency, in the middle of an investigation into Russian interference in the 2016 election.
Mr Trump and his supporters labelled the investigation a "hoax" and a "witch hunt" despite several government reviews showing that Moscow interfered on behalf of the Republican's campaign.
The charges come days after the US president appeared to chide his attorney general, Pam Bondi, for not bringing criminal charges against Comey and other perceived political enemies quickly enough.
"No one is above the law," Bondi said in a social media post on Thursday. "Today's indictment reflects this Department of Justice's commitment to holding those who abuse positions of power accountable for misleading the American people."
The criminal case against Comey, who served as FBI director from 2013 to 2017, does not concern the substance of the Russia investigation.
Instead, it accuses him of having lied to a Senate committee in 2020 when he said he never authorised anyone to serve as an anonymous source to a reporter about the investigation.
After he was fired, Comey became a prominent critic of the president, calling him "morally unfit" for office.
Meanwhile, another former FBI chief, Robert Mueller, was appointed as a special counsel to take over the investigation into Russian election interference.
While the probe found numerous contacts between Trump's 2016 campaign and Russian officials, it concluded that there was not enough evidence to establish a criminal conspiracy.
The case against Comey is the starkest example of the Trump administration using law enforcement to target a critic, following the president's promise of retribution against the former FBI chief during his 2024 election campaign.
If Comey is convicted of making a false statement and obstruction, he faces up to five years in prison.
This breaking news story is being updated and more details will be published shortly.
Please refresh the page for the fullest version.
You can receive breaking news alerts on a smartphone or tablet via the Sky News app. You can also follow us on WhatsApp and subscribe to our YouTube channel to keep up with the latest news.