A former congressional aide pleaded guilty on Wednesday to charges of conspiracy to commit bribery and aiding and abetting the solicitation of bribes by a member of Congress.
Brett Pfeffer , a former aide to Rep. William Jefferson , D-La., entered his plea deal in U.S. District Court in Alexandria, Va. Pfeffer faces up to 20 years in prison when sentenced March 31 and a fine of up to $500,000.
"Today this defendant admitted to a crime which, at its core, is a bribery scheme involving a public official," said Assistant Attorney General Alice Fisher of the Criminal Division. "Such schemes deprive citizens of the integrity and honest services expected of our government. The Justice Department will aggressively investigate and prosecute these illegal schemes."
Pfeffer, who worked as a legislative assistant for Jefferson from 1995 to 1998, must cooperate with officials in an ongoing investigation, according to the plea deal.
"The congressman told me of a business opportunity in Nigeria," Pfeffer told Judge T.S. Ellis. "I took that opportunity to a woman I work for. She decided to invest in this company. [Jefferson] would require 5 to 7 percent of the company for his family. In exchange, he would work with officials in Nigeria to further the business."
Prosecutor Mark Lytle said the congressman and Pfeffer traveled to Ghana in July to promote a similar deal there.
Pfeffer, 37, told officials that Jefferson accepted bribes in connection to supporting a telecommunications agreement with the Nigerian government. The court documents do not name Jefferson specifically but refer to him only as "Representative A."
The documents make obvious that Jefferson is the congressman who allegedly solicited the bribes, which was initiated by the Kentucky-based company, and received monthly payments of $2,500 to $5,000 for his family members between 2004 and August 2005.
In August, the FBI searched Jefferson's Louisiana home and Nigerian Vice President Atiku Abubakar's Maryland residence. Jefferson was first elected to Congress in 1990, becoming the first black Louisiana congressman since Reconstruction. He was criticized after Hurricane Katrina for getting the National Guard to escort him to his flooded home at a time when federal resources were sorely strained.
Pfeffer's attorney, Paul Knight, and Jefferson's spokeswoman, Melanie Rousell, declined comment.
Jefferson was unable to comment on Wednesday because he was traveling in the Netherlands with Sen. Mary Landrieu, D-La., to review levee systems. Jefferson is expected back on Thursday to attend a hearing in Louisiana.
The bribery probe is separate from the ongoing investigation of lobbyist Jack Abramoff , who pleaded guilty last week to federal charges. Abramoff's investigation could bring down some lawmakers and their aides, including a former aide to Rep. Tom DeLay, R-Texas.
The investigation has looked into Jefferson's dealings with a privately held technology company, iGate Inc. in Louisville, Ky., which was seeking telecommunications contracts in Nigeria.
FOX News' Molly Hooper and The Associated Press contributed to this report.