The U.S. State Department said Friday that the passport files of all three remaining presidential candidates had been improperly breached by contract workers.  The revelation prompted an apology from Secretary of State Condoleezza Rice and the promise of a full investigation by the State Department.  VOA National correspondent Jim Malone, in Washington, has more on this latest turn in the U.S. presidential race.

The State Department first announced that the passport file of Senator Barack Obama had been breached three times since January this year.  The department says two contract workers were dismissed in connection with those incidents and a third was reprimanded.

A department spokesman later acknowledged that Senator Hillary Clinton's passport file had also been breached last year.

Campaigning in Oregon, Obama told reporters he expects a full and thorough congressional investigation.

"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, then it is going to stay personal and stay private," he said.

State Department spokesman Sean McCormack also said that one of the contract workers who had accessed Senator Obama's file had also improperly breached the file of the presumptive Republican presidential nominee, Senator John McCain.

McCain was traveling in France and said the breach incidents require an apology and a full investigation.

"The United States of America values everyone's privacy and corrective action should be taken," he said.

Spokesman McCormack said the State Department's office of inspector general is already investigating the incidents and whether they were politically motivated.

"And I have to tell you that we take very seriously the trust that is put in us in safeguarding American citizens personal data," he said.

Secretary of State Rice expressed regret about the incidents in phone calls to all three presidential candidates, including Senator Obama.

"I told him that I, myself, would be very disturbed if I had learned that somebody had looked into my passport file," she noted.  "And therefore, I will stay on top of it and get to the bottom of it."

The State Department is responsible for issuing passports in the United States.  Passport files usually contain personal identity information and may include information about countries the person has traveled to.

State Department officials became aware of the breaches from a computer monitoring system that flags attempts to access the passport files of high profile people like politicians and celebrities.

Meanwhile on the presidential campaign trail, Senator Obama got a boost Friday when one of his former rivals, New Mexico Governor Bill Richardson, endorsed him during a campaign rally in Portland, Oregon.

"Barack Obama will be a great and historic president who can bring us the change we so desperately need by bringing us together as a nation here at home and with our allies abroad, and I know all Democrats and all Americans are going to work tirelessly to get this man elected!" he said.

Richardson dropped out of the Democratic presidential race in January and had previously served in cabinet positions in the Clinton administration.

Political analysts say the Richardson endorsement could help Obama win over more so-called super delegates, Democratic Party activists and office holders who will attend the national nominating convention in August as uncommitted delegates.

Ron Walters is a professor of government and politics at the University of Maryland.

"This comes at a pivotal time because Barack Obama has been suffering from some negative publicity, and for a governor to step up and endorse him gives confidence to the other party leaders that they are moving in the right direction," he explained.

The Clinton campaign hopes to stem the flow of super delegates to Obama with a strong showing in the Pennsylvania presidential primary on April 22 where recent polls give her a sizeable lead.

Obama continues to lead the delegate count, but neither contender will be able to secure the party nomination before the August convention without considerable support from uncommitted super delegates.