CHICAGO (CBS) — Federal workers who received state unemployment benefits during the federal government shutdown, but who later received back pay, must repay the state of Illinois soon.

WBBM Newsradio Political Editor Craig Dellimore reports about 3,000 federal employees applied for state unemployment aid during the 16-day partial shutdown of the federal government. About 600 of them got checks, totaling $230,000.

However, after the shutdown ended, Congress voted to grant back pay to workers for the time they were forced off the job.

Jay Rowell, director of the Illinois Department of Employment Security, said those workers must give back the unemployment benefits they received.

“You cannot be receiving unemployment insurance benefits at the same time you’re receiving a paycheck,” he said. “We’re committed to protecting the taxpayer dollar, and trying to safeguard every penny, and so we’re going to make an effort here to get all those funds back.”

Rowell said he hopes the workers return the money voluntarily, and expects most of them will. He stressed the workers did nothing wrong by collecting unemployment during the shutdown.

“They were looking at not being sure when they were going to get their next paycheck, but still having to put food on the table. So they applied for unemployment insurance benefits,” he said. “Typically, if there’s a layoff, or some other type of shutdown, the employees aren’t given back pay.”

If those workers don’t pay back the unemployment benefits they received, the state can garnish their income tax refunds, or use other collection methods to get the money back.