Barack Obama secured a loan on his $1.65 million Chicago mansion at a discounted rate that could have saved him more than $300 per month, The Washington Post reported Wednesday.

The newspaper reported that the presumptive Democratic presidential nominee locked down a $1.32 million loan from Northern Trust at an interest rate of 5.625 percent in June 2005, shortly after he entered the U.S. Senate.

The Post said the rate on the 30-year fixed-rate mortgage was "below the average for such loans at the time in Chicago," and that similar loans would have been available at rates as high as 6 percent.

But Obama spokesman Ben LaBolt told FOX News there was nothing unusual about the mortgage and that "anyone with the Obamas' financial profile could have gotten the same rate on that mortgage."

LaBolt said Barack and Michelle Obama were flush with cash at the time they went loan shopping and that Northern Trust sought their business by offering a lower mortgage rate -- in part to respond to a competitive mortgage rate offered by another lender. LaBolt would not identify the other lender.

The Obamas' income was rising when they secured the loan. Barack Obama had cash from a $2.2 million book deal with Random House signed in January 2005. Michelle Obama doubled her income to $317,000 when she received a promotion at the University of Chicago Hospital system.

Northern Trust released a statement saying "the process for determining the Obamas' mortgage loan was consistent with how we structure Northern Trust rates, and the rates themselves were consistent with Northern Trust rates at that time."

Information about the Obamas' home purchase can be found at the campaign Web site.

LaBolt said any accusation that Obama received favorable treatment is false.

Such accusations are a sensitive matter, after it was reported that Jim Johnson -- the former Fannie Mae CEO who was previously vetting Obama's running mate prospects -- received favorable loan terms from Countrywide Financial. Johnson left his post on the campaign after the report was published.

Countrywide reportedly has a "VIP" program, under which well-connected or high-profile borrowers can receive special rates.

Northern Trust said it does not have such a program.

Click here to read more on the Obama loan terms on Major Garrett's blog.

Click here to read the original Washington Post story on the loan.

FOX News' Major Garrett contributed to this report.