Billionaire investor and former Donald Trump consultant Thomas Barrack have denied allegations of being a foreign government agent.
Mr. Barrack, 74, was a key supporter of Mr. Trump during his 2016 campaign.
He has been accused of illegal lobbying on behalf of the United Arab Emirates (UAE) during and after the election, as well as lying to the FBI.
Mr. Barrack denied the allegations while in court for the first time on Monday.
The former Trump official faces charges of conspiracy, obstruction of justice, and making numerous false statements to the FBI during a 2019 interview and was arrested in California last week.
When he left court on Monday, Mr. Barrack told reporters: "As you can see, the system is working ... you will all find me 100 percent innocent."
An employee of Mr. Barrack, Matthew Grimes, also faces charges of illegal persuasion and denied allegations against him on Monday.
A UAE national, Rashid Sultan Rashid Al Malik Alshahhi, 43, was also charged although he has not yet been arrested.
The three men are accused of illegally trying to promote the interests of the UAE government by using Mr. Barrack's links to persuade officials to appear in the media.
They also allegedly campaigned for the UAE's preferred candidate as US ambassador to Abu Dhabi.
Mr. Barrack, who also served as chairman of the inaugural committee of Mr. Trump, has been friends with the former president for four decades.
The wealthy investor is a former Trump aide facing criminal charges recently as former campaign chairman Paul Manafort and former Trump Corporation lawyer Michael Cohen.
He is expected to appear in court again on September 2.
Mr. Barrack has now been released on $ 250m bails but must wear an elbow bracelet with electronic GPS, which prevents him from traveling and also follows a curfew.
