Purdue University is alerting employees that their personal information might have been illegally accessed from the school's computer system.

It was the third time in the past year that Purdue has discovered a computer security breach, school officials said Friday.

"Our investigation of a recent information technology security breach shows that the records of 11,360 current and former employees may have been accessed electronically," said James Bottum, vice president for information technology. "We do not know how or whether the intruders intend to use this information, but we are alerting everyone who may have been affected because this information could be used to commit identity theft.

The most recent security breach spanned a 17-day period before it was discovered May 5, school officials said.

Someone infiltrated computers used by software developers who were testing programs for the university's purchasing system.

Purdue began in 2003 to remove Social Security numbers from employee information in order to limit identity theft, but the process is not yet complete, said Morgan Olsen, the school's executive vice president and treasurer.

Employees were asked to visit a Web site, http://www.purdue.edu/dataincident/, to determine whether their information may have been accessed. The site gives employees a list of steps on what to do to prevent identity theft.