A panel of law enforcement experts found that U.S. Customs and Border Protection has made little movement on a call to sharply increase the number of agents assigned to investigate internal corruption, calling it a mistake that could lead to a major scandal if it isn't addressed more quickly.

The Customs and Border Protection Integrity Advisory Panel last year urged the nation's largest law enforcement agency to more than double the number of internal affairs criminal investigators to 550. It says the agency's 2017 budget calls for an increase of only 30 investigators, meaning it would take about a decade to hit that mark.

A massive hiring surge over the last decade has fueled concerns about corruption, use of force and lack of transparency at Customs and Border Protection.