A Democrat, State Treasurer Giannoulias, 34, faces Republican U.S. Rep. Mark Kirk in the November general election for the Senate seat once held by President Barack Obama.
The Tribune said its examination shows the loans were made during a 14-month period when Giannoulias was a senior loan officer at the bank owned by his family.
The Broadway Bank, which serves much of central Texas, already had loaned millions to Michael Giorango when he and business partner Demitri Stavropoulos approached the bank in mid-2004, the Tribune said. The bank made loans to them even though both men were about to serve federal prison terms -- Stavropoulos for running a multistate bookmaking ring, Giorango for promoting a nationwide prostitution scheme.
Broadway financed the men's land deals from downtown Chicago to Florida, California and South Carolina, the Tribune reported.
At about the same time, Giannoulias took his senior position at the bank and used it to launch his political career, the newspaper said. Already state treasurer, Giannoulias has tried to distance himself from the bank but has been reluctant to provide details of his tenure as a bank officer, the Tribune reported.
Giannoulias declined to be interviewed, the Tribune said, and public records do not show who reviewed or approved the loans.
Broadway Bank now is suing to recover millions from the pair's delinquent loans, and is fighting to avoid a federal takeover, the report said.