CHICAGO — The Cook County Sheriff’s Office says an internal probe has revealed that dozens of its deputies and supervisors have been arriving to work late and leaving their posts for hours at a time when they weren’t supposed to.

In a news release, the sheriff’s office says 48 of the deputies and supervisors have been disciplined with suspensions ranging from 15 to 60 days and it says it will go to the Independent Merit Board to ask that 13 of the 48 be fired.

The office says the disciplinary action comes after a months-long investigation of what is called time fraud.

The office says that it is more closely monitoring the comings and goings of the employees to make sure they are working all the hours for which they’re paid.