The files -- published in several U.S. and European newspapers -- contain information on all 779 people who have passed through the U.S. prison facility since it was opened in 2002.
"The Guardian" -- one of the newspapers who published the files -- says the files show that about 220 detainees were classed as dangerous terrorists but that 150 were innocent Afghans and Pakistanis, including farmers, drivers, and chefs.
It says the files show that another 380 people were deemed to be low-ranking foot soldiers.
The U.S. Defense Department described the leak as "unfortunate" and said many of the assessments are incomplete.
More than two years after President Barack Obama ordered the prison closed, 172 detainees are still being held at the U.S. naval base in Cuba.
compiled from agency reports