Confidential information about hundreds of Fairfax County high school students was leaked and posted online, where the information remained Thursday night as the school system and city police started an investigation.

The names, student identification numbers and several grades earned by students at Fairfax High School were posted on a website, grouped by course. The leak involves ninth-through-11th-grade students, displaying their final exam grades, fourth-quarter grades and final grades for the 2011-12 school year.