Obama is calling for a congressional investigation.

(CNN) - Sen. Barack Obama Friday called for an investigation into how the security of the passport files of the three remaining presidential candidates was breached.

The State Department admitted Friday that the passport files of Obama, Sen. Hillary Clinton and Sen. John McCain had been accessed without authorization.

"One of the things that the American people count on in their interactions with any level of government is that if they have to disclose personal information that it stay personal and stay private," Obama said in Portland, Oregon.

"And when you have not just one but a series of attempts to tap into people's personal records, that's a problem not just for me, but for how our government is functioning," he said.

Obama said he expected "a full and thorough investigation" by the administration done in conjunction with congressional oversight committees.

The State Department's inspector general has already started an investigation, department officials said.

Attorney General Michael Mukasey said the Justice Department had not launched an investigation and did not expect to unless it was asked by the inspector general.

Obama is looking to quell controversy over a remark he made about his grandmother.

(CNN) - At the tail end of a week spent addressing the thorny issue of race in America, Barack Obama is responding to fresh criticism for using the words “typical white person” in reference to his grandmother during a radio interview.

Thursday night, Obama told CNN’s Larry King that “what I meant really was that some of the fears of street crime and some of the stereotypes that go along with that, you know, were responses that I think many people feel. She's not extraordinary in that regard. She's somebody who I love as much as anybody. I mean, she has literally helped to raise me. …

“And so the point I made is that good people, people who are not in any way racist, are still subject to some of these images and stereotypes and that it's very hard to escape from them,’’ Obama said.

Obama, who mentioned his grandmother during a speech on race he delivered in Philadelphia Tuesday, had told the hosts of a sports radio show in that city that his grandmother was not a racist, “…but she is a typical white person who, you know, if she sees somebody on the street that she doesn’t know, there is a reaction that has been bred into our experiences that don’t go away and sometimes come out in the wrong way…”

He added that that was the “nature of race in our society, and we have to break through it,” saying that he saw each generation “feeling a little less like that.”

Conservative critics immediately reacted, saying his use of the phrase “typical white person” was a racist characterization.

When King asked if the comment might hurt his campaign, Obama responded: “I think that my campaign has always been built on a confidence in the American people, that we can talk honestly about issues, that we can acknowledge that they're complicated, that we can disagree without being disagreeable…”

Race has come to the forefront in the Democratic race recently, with comments by Clinton supporter Geraldine Ferraro that Obama would not be a major presidential candidate if he were white, and a new focus on the controversial remarks about 9/11 and other issues by the Illinois senator’s former minister, Rev. Jeremiah Wright.

Watch Obama explain his comments on Larry King Live here.