NBC CHICAGO -- Federal prosecutors and FBI agents in Washington have launched a new criminal investigation of Illinois Rep. Jesse Jackson, Jr. involving financial improprieties, including possible misuse of funds monitored by Congress, law enforcement sources tell NBC News.
The probe prompted lawyers for Jackson to meet with federal prosecutors this week in an attempt to persuade them not to indict the congressman.
Jackson's lawyers did not return email and phone call request for comment.
The sources, confirming an account in the Chicago Sun-Times, said the new probe is being run out of the U.S. Attorney's Office in Washington, D.C. The Sun-Times report cited sources who said the probe focusing on "suspicious activity" was launched shortly before Jackson's sudden leave of absence in June.
Reached by phone, Jackson's top aide, Frank Watkins, told NBC Chicago he learned of the investigation by the Sun-Times and had no other information.
Watkins said Jackson hasn't been to the office and that he has "very little" contact with the congressman.
"I wait for him to call me," he said, adding that Jackson "sounds fine" when they speak.
"I've consistently been told he's under doctor's care, and when the doctors release him, he will come back to work," he said.
At the same time, a House Ethics Committee continues to look into Jackson's supposed involvement in trying to be appointed to now-President Barack Obama's seat in the U.S. Senate. Jackson has admitted he wanted to be appointed to the Senate, but has repeatedly denied allegations he sent emissaries to offer campaign cash to then-Gov. Rod Blagojevich in exchange for the seat.
Jackson stopped working on June 10, his staffers revealed two weeks later in a three-sentence memo. He first obtained treatment at a facility in Arizona before transferring to the famed Mayo Clinic in Rochester, Minn., where doctors said he had "depression and gastrointestinal issues."
He left Mayo Clinic and went back to Washington, D.C. in early September but has not returned to work. Citing mounting medical bills, Jackson and his wife, Ald. Sandi Jackson (7th), briefly put their D.C. home on the market.
Though he's not done any campaigning, Jackson remains on the November ballot for the Illinois 2nd Congressional district.