Washington (CNN) Informants at risk of losing awards. A growing backlog of evidence untested. Assistance in an international kidnapping case turned down.

As the partial government shutdown continues without an end in sight, FBI agents say that lack of funding is hurting the nation's premier law enforcement agency.

Nearly 5,000 special agents, intelligence analysts, and support staff are among the hundreds of thousands of federal employees told they can't show up to work as President Donald Trump and congressional leaders fight over appropriations bills and the border wall.

"Operations are being hindered," said Tom O'Connor, president of the FBI Agents Association, which represents most of the bureau's active duty special agents. "We believe strongly that the FBI, as a national security organization, we need to be fully funded."

At the FBI, a limited budget for operations means active investigations are losing support, according to law enforcement officials who spoke to CNN on the condition of anonymity and the agents association.

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