Updated

Illinois officials have taken the unusual step of searching prison guards and other employees for contraband as they're leaving work.

The Associated Press has learned at least seven prisons conducted shakedowns last week. Workers and their union say the unusual end-of-shift checks are retaliation for whistleblowers speaking out about crowded prisons and Gov. Pat Quinn's plan to close the "supermax" Tamms lockup.

Department of Corrections spokeswoman Stacey Solano says the searches are routine and meant to stop "movement" of contraband — from cellphones to weapons — in the prisons. She denied retaliation plays a role.

The department has the right to search employees at any time. But workers say they've never been patted down at the end of work and question whether officials are looking for people leaking confidential information.