Two men who are accused of posing as federal agents and lavishing gifts on US Secret Service agents, including one assigned to first lady Jill Biden, pleaded not guilty on Tuesday to the criminal charges.
The men gave their pleas in an online hearing in the US District Court for the District of Columbia.
Arian "Ari" Taherzadeh and Haider Ali were arrested in April, two days after four Secret Service agents were placed on leave for allegedly accepting gifts including iPhones and rent-free apartments at a luxury complex in south-east Washington.
In a search of apartments leased under the name of Mr Taherzadeh's company, US Special Police, the FBI said it found firearms, surveillance equipment, hard drives, law-enforcement gear and equipment for making identity cards.
The two men are also charged with the unlawful possession of a large-capacity ammunition feeding device.
In an amended sworn statement filed in court last week, the FBI said that Mr Taherzadeh and Mr Ali posed as agents with the Department of Homeland Security and employees from the Justice Department and the Office of Personnel Management.
They also offered gifts or favours to employees of other federal agencies who lived in the apartment complex, including the FBI and the Department of Defence, the statement said.
Last week, Reuters reported that Mr Taherzadeh previously posed as a wealth IT executive.
Court records show that Mr Taherzadeh racked up more than $1 million in debt for unpaid rent from apartment complexes, luxury cars, VIP box seats at Capital One Arena, and a sponsorship deal with the company that owns several of Washington's professional sports teams.