The U.S. State Department says the passport files of all three presidential candidates have been breached.
State Department spokesman Sean McCormack Friday said there will be a full investigation by the department's inspector general.
McCormack says Secretary of State Condoleezza Rice spoke with both Democratic Party presidential hopefuls - Barack Obama and Hillary Clinton - and will speak with Republican candidate John McCain, who is in Paris.
McCormack says the same contract employee who examined Obama's file also looked at McCain's passport file. He says senior management was only informed of the breaches when a reporter called inquiring about the matter.
The State Department says it dismissed two contract workers and disciplined a third for the unauthorized viewing of the files. A spokesman for Obama's campaign, Bill Burton, described the incident as an "outrageous breach of security and privacy."
An automatic system that records any attempt to access the files of prominent Americans reported three intrusions of Obama's file this year, beginning on January 9.
McCormack previously said there is no indication that there was any political motivation behind the incidents. The State Department did not identify the workers or their office.
Some information for this report was provided by AP.