"My relationship is he was somebody who I knew and had been a supporter for many years, he was somebody who had supported a wide range of candidates all throughout Illinois," the Democratic presidential candidate said in an interview with CBS News' The Early Show. "Nobody had an inkling that he was involved in any problems. When those problems were discovered, we returned money from him that had been contributed."
Obama, an Illinois senator, also said it was a mistake for him to have purchased a strip of land from Rezko's wife. The land adjoins the Obamas' Chicago home. Rezko was widely reported to be under grand jury investigation at the time.
"Everything was above board and there's been no allegations that it wasn't," Obama told Early Show co-anchor Harry Smith.
"In terms of appearances, and I've already said this, that I should not have entered into any kind of agreement with him," Obama added on ABC's "Good Morning America."
Obama also has given to charity about $37,000 in contributions to his Senate campaign and political action committee that were linked to Rezko. Rezko also raised tens of thousands of dollars for Obama's state legislative and Senate races.
Rezko faces a Feb. 25 trial, almost three weeks after the Super Tuesday primaries that could go a long way in settling the Democratic nomination. He is charged with fraud, attempted extortion and money laundering for allegedly plotting to get campaign money and payoffs from firms seeking to do business before two state boards.
Once that trial is behind him, the 53-year-old Rezko faces a separate federal charge of swindling the General Electric Capital Corp. out of $10 million in connection with the sale of pizza restaurants.
Obama's name has not come up in connection with any of the corruption charges swirling around Rezko. In fact, prosecutors indicate the source of Rezko's clout was somewhere within Democratic Gov. Rod Blagojevich's administration.
Presidential rivalraised Obama's relationship with Rezko in a .