Steve Bannon, the former chief strategist of President Donald Trump, has pleaded not guilty to a fraud charge relating to fundraising for the controversial Mexico border wall.
In Bannon's first court appearance - just hours after his arrest - a US judge approved bail conditions and agreed a $5m bond.
The US Department of Justice said the charge relates to We Build The Wall, a fundraising campaign to support the building of a border wall between the US and Mexico.
Federal prosecutors alleged that Bannon, along with three others, "orchestrated a scheme to defraud hundreds of thousands of donors" in connection with the online crowdfunding campaign, which raised more than $25m (£19m).
The news came as Donald Trump's bid to block being forced to reveal eight years of personal and corporate tax records was dismissed by a judge.
The charges against Bannon and three others were contained in an indictment unsealed in Manhattan federal court.
According to the indictment, Bannon promised that 100% of the money donated would be used for the project, but the defendants allegedly used hundreds of thousands of dollars in a manner inconsistent with the organisation's public representations.
They allegedly faked invoices and sham "vendor" arrangements in a bid to hide what was really happening, the indictment added.
We Build The Wall originally promoted a project for three miles of fences posts in South Texas, a project that was built and largely funded by Fisher Industries.
The company, which has received around $2bn (£1.5bn) in funding for wall contracts, did not respond to calls for comment.
Mr Trump recently criticised that section of the wall after it displayed signs of erosion, saying it was "only done to make me look bad", even though it was built by his supporters.
And responding to news of the charge against his former aide, the president said: "It's a very sad thing. I haven't been dealing with him for very long period of time.
"I don't know anything about the project at all. I don't like that project. I thought it was being done for showboating reasons. I thought it was inappropriate to be doing."
Bannon was appointed chief executive of Mr Trump's successful presidential campaign in 2016, leaving his role at conservative website Breitbart News to join the campaign.
He became chief strategist for Mr Trump after his inauguration, but Bannon clashed with others in the White House and was pushed out in August 2017.
Bannon returned to Breitbart, but left again the following year after being quoted in Michael Wolff's explosive book, Fire And Fury: Inside The Trump White House.
He was quoted questioning his former boss' mental stability and claimed those close to the president described him as a "moron, an idiot".
Bannon later expressed "regret" over his place in the book.