Senators from both parties on Sunday urged the Department of Justice to investigate the unauthorized searches of the passport files of three presidential candidates by State Department workers.

"That kind of a breach of privacy is just despicable," said Pennsylvania Sen. Arlen Specter, the top Republican on the Senate Judiciary Committee. "I think that ought to be a very intense investigation."

Sen. Ron Wyden, D-Ore., agreed, saying the incidents seem to point to a broader problem.

The Government Accountability Office has been warning about this problem for a decade. And it seems to me in this administration, there's been pretty much a culture of disregard for privacy, and that's part of the problem," he said.

Both senators spoke on CNN's "Late Edition."

The State Department's investigation into how and why the passport files of three presidential candidates were breached is scrutinizing an employee at a Virginia-based company, which is headed by an adviser to Barack Obama's campaign.

The Washington Times, which broke the news Thursday that Obama's files were improperly accessed, reported Saturday that the State Department inspector general's internal probe will include polygraph tests of supervisors to determine whether there was a political motive behind the breaches.

The article said a focal point of the probe will be an employee who works for The Analysis Corporation and is still with the company. The firm is headed by John O. Brennan, an Obama adviser, FOX News confirms. The Times reported he advises the Democratic presidential candidate on intelligence and foreign policy matters.

The Times reported that the employee at TAC is the only individual who accessed both Obama's and John McCain's passport information. TAC decided to honor a State Department request to delay firing the consultant to give investigators time to conduct their investigation, the company said.

Two other contract workers were fired from Stanley Inc. after it was discovered they accessed Obama's files. It could be challenging for the State Department to force them to answer questions, however. Unless they volunteer to cooperate, they would have to be served with a subpoena compelling them to testify before a grand jury.

Obama's campaign at first questioned whether the senator was targeted for political reasons, but on Friday the State Department revealed Sens. Hillary Clinton and McCain also had their files improperly accessed. The State Department believes the cases could be just a matter of "imprudent curiosity," but the internal investigation and a separate congressional probe are expected to delve into whether it was anything more.

"There are still many unanswered questions, including why these passport files were accessed and for what purpose," Obama's office said in a statement late Friday. "Sen. Obama believes a thorough investigation of these privacy breaches is necessary and expects one that is prompt and thorough."

A fourth worker tapped into Clinton's records as part of a training session last summer, the State Department said, and that violation was immediately recognized and the person admonished.

The Justice Department is monitoring the effort.

"None of us wants to have a circumstance in which any American's passport file is looked at in an unauthorized way," Secretary of State Condoleezza Rice said as she offered apologies to the candidates.

The unauthorized digging into electronic government files on politicians recalled a 1992 case in which a Republican political appointee at the State Department was demoted for searching Bill Clinton's passport records when Clinton was running against President George H.W. Bush.

Obama's files were compromised on three occasions -- Jan. 9, Feb. 21 and March 14. The department's internal computer system "flags" certain records, including those of high-profile people, to tip off supervisors when someone tries to view the records without an appropriate reason.

It was not clear whether the employees saw anything other than the basic personal data such as name, citizenship, age, Social Security number and place of birth, which is required when someone fills out a passport application.

The files also include date and place of birth and address at time of application. Agency officials said the files generally would not list countries the person has traveled to.

Attorney General Michael Mukasey said the case has not yet been referred to the Justice Department for investigation, but he did not rule out the possibility of the Justice Department taking an independent look.

Click here to read the article in The Washington Times.

The Associated Press contributed to this report.