As part of a federal racketeering case against him, a Pennsylvania congressman reported to a Philadelphia court building on Tuesday to be photographed and fingerprinted, the Associated Press reported.

Prosecutors are accusing Democrat Chaka Fattah of having paid off an illegal campaign loan with federal grants and charitable donations, and of having funneled campaign funds toward his son's student loan. The 58-year-old representative will fight the charges at trial, his lawyer, Kevin Mincey, told the newswire.

The congressman said on Monday that the officials investigating him had used "unconstitutional and unlawful" threats and questionable motives to build their case, the Philadelphia Inquirer noted. Fattah accused Paul Gray, the assistant U.S. attorney handling his case, of generating a politically charged feud against earmarks the prosecutor perceived to be corrupt.

"This approach is one that is most strikingly consistent with (Department of Justice) misdeeds in multiple recent cases targeting members of Congress," Fattah wrote in a five-page letter addressed to the leaders of the House Committee on Oversight and Government Reform.

"Some in the (department) may have potentially blurred the lines of the separation of powers, engaged in tactics with the intention to influence a political process, and performed other documented examples of misconduct," he added.

His missive accused prosecutors of having improperly approached witnesses without their lawyers, violating grand jury secrecy laws in an effort to embarrass him, using threats to coerce him into producing congressional documents protected under the Constitution and making false statements in court, the newspaper enumerated.

A federal grand jury, on July 29, had indicted the 11-term congressman on charges of bribery, racketeering, money laundering, bank fraud, filing false statements, as well as mail and wire fraud, Polito recalled. If convicted, he could face up to 30 years in prison.

According to the U.S. Attorney's office, Fattah obtained an illegal $1 million loan during his 2007 bid for mayor of Philadelphia and then improperly used federal and charitable funds to help repay the debt. The congressman also went to great lengths to cover up his wrongdoing, prosecutors alleged.