SPRINGFIELD, Illinois (CNN) - Rep. Jesse Jackson Jr. - who was cited in a criminal complaint against Rod Blagojevich - has been an informant for at least a decade with the U.S. Attorney's office, and has informed on the embattled governor of Illinois, though not in the case currently under investigation, Jackson spokesman Kenneth Edmonds told CNN Tuesday.
In addition, two sources close to Jackson told CNN that, in 2002, Blagojevich - then running for governor of Illinois - solicited a $25,000 campaign donation from Jackson, which he did not get.
At the time, Jackson's wife, Sandi, was a candidate for the job of director of the state's Lottery Commission, a post she did not win, the sources said.
After Blagojevich took office, in early 2003, he told Jackson something to the effect of, "You see what $25,000 would have done?" the sources said.
In 2006, Jackson reported the incident, which he believed to have been an attempt at a shakedown, the sources said.
The report, the sources said, came three three years later because Jackson's memory was jogged by another case - that of developer Tony Rezko, whose fraud and corruption trial included testimony about $25,000 donations to Blagojevich.
Jackson did not endorse Blagojevich in his initial campaign and tried to stay on the sidelines during the governor's re-election bid, one of the sources said.
Blagojevich's office did not return calls seeking comment.