Washington (CNN) More than a month after the longest government shutdown in US history ended, a significant number of Transportation Security Administration employees still have not received all of the back-pay they are owed.

The delay has been caused in part due to an unusual move during the shutdown to pay a partial paycheck to workers in order to help keep them on the job. TSA Administrator David Pekoske told employees at the time the decision was to "alleviate some of the financial hardship many of you are facing." Hundreds of TSA workers called out from work during the shutdown and officials from the national TSA employee union said many of the callouts were due to financial hardship.

According to a source with knowledge of the situation who was not authorized to speak to the media, more than 1,000 TSA employees are still waiting to be paid in full. The exact number is unclear as employees continue to come forward with complaints that they are still owed money from the shutdown.

During the partial government shutdown, which lasted from December 22 until January 25, CNN was first to report hundreds of TSA screeners were not showing up to work as it became more difficult to make ends meet for many employees without their usual paycheck. The staffing shortages caused long lines at some airports during the 35-day shutdown and even forced some of those airports to shutdown security checkpoints.

When the shutdown ended, President Donald Trump said issuing back pay to federal employees would be the priority, and the Office of Management of Budget instructed agencies to prioritize repaying its employees.

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