WASHINGTON: A congressional staffer of Pakistani origin, arrested and released in the US capital on Tuesday, faces a criminal investigation impacting dozens of Democratic lawmakers, the US media reported.

Imran Awan was arrested earlier for an alleged bank fraud and was prevented from leaving the country while the charges are pending. He worked for Congresswoman Debbie Wasserman Schultz, a Florida Democrat.

But David Damron, a spokesman for the US lawmaker, later said that Mr Awan was fired on Tuesday.

Mr Awan`s attorney Chris Gowen, however, sent an email to variousUS media outlets on Tuesday afternoon, saying: `This is clearly a rightwing media-driven prosecution by a United States Attorney`s Office that wants to prosecute people for working while Muslim.

He said that even a quick glance at what the government filed in court on Tuesday confirmed lack of evidence or proof against his client.

Earlier on Tuesday, Mr Awan pleaded not guilty to one count of bank fraud during his arraignment inacourtintheDistrictof Columbia.

Mr Awan is accused of attempting to defraud the Congressional Federal Credit Union by obtaining a $165,000 home equity loan for a rental property, against the credit union`s policies since it is not the owner`s primary residence. Thosefunds were then included as part of a wire transfer to two individuals in Faisalabad.

Mr Awan was arrested at Washington`s Dulles Airport on Monday evening before boarding a flight to Lahore. His wife, Hina Alvi, has already left the US for Pakistan along with their children.

A court document showed US federal agents telling the court that Ms Alvi had no intention of returning to the US.

Mr Awan was release d on Tues day on a `high-intensity supervision programme`, according to a spokesman. He must wear a GPS monitor, abide by a curfew of 10pm to 6am and cannot leave a 50-mile radius of his Lorton, Virginia, home. He was also forced to surrender his pass-ports and is scheduled to reappear in court for a preliminary hearing on Aug 21.

Mr Awan, a longtime IT staffer who worl(ed for more than two dozen House Democrats, has been at the centre of a criminal investigation on Capitol Hill for months.

It is related to procurement theft.

Several of his family members, also IT staffers at the time, were implicated in the ongoing investigation.

Ms Alvi, another House staff member involved in the Capitol Hill investigation, left the country with their three daughters, headed for Pakistan in March. She took more than $12,000 in cash, FBI agent Brandon Merriman wrote in an affidavit submitted in the court.