WASHINGTON — The State Department said last night that it had fired two contract employees and disciplined a third for accessing Senator Obama’s passport files.

Mr. Obama’s presidential campaign immediately called for a “complete investigation.”

State Department spokesman Tom Casey said the employees had individually looked into Mr. Obama’s passport file on January 9, February 21, and March 14. To access such a file, the employees must first acknowledge a pledge to keep the information private. The employees were each caught because of a computer-monitoring system that is triggered when the passport accounts of a “high-profile person” are accessed, he said. The system, which focuses on politicians and celebrities, was put in place after the State Department was embroiled in a scandal involving the access of the passport records of then-presidential candidate Bill Clinton in 1992.

“The State Department has strict policies and controls on access to passport records by government and contract employees,” Mr. Casey said.

The department uses contract employees to help with data entry, customer service, and other administration tasks. The employee involved in the March 14 incident has only been disciplined so far, because the investigation of that incident is still continuing, an official said.

Though the workers were caught by a computer system that focuses on high-profile people, Mr. Casey said that a computer report is generated on every access to passport records and that spot checks are taken to ensure that employees are not violating the Privacy Act. “This is an outrageous breach of security and privacy, even from an administration that has shown little regard for either over the last eight years,” Obama spokesman Bill Burton said in a statement. “This is a serious matter that merits a complete investigation, and we demand to know who looked at Senator Obama’s passport file, for what purpose, and why it took so long for them to reveal this security breach.”