The FBI and the Niagara County Sheriff's released a joint statement following an incident last December that caused several federal and local law enforcement officers to become ill. 

The incident happened December 14. 

Law enforcement officials conducted a raid at 4 Packard Court in Niagara Falls. 

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Following the raid, several officers and investigators became ill with various symptoms.  Offficials say 21 people, including some who did not enter the house, reported feeling ill.  Eighteen people did not report getting sick. 

The 914th Air Force Reserve and Niagara County Hazmat entered the property nearly two weeks later to take samples for testing.  All collected samples came up negative. 

Those who reported feeling ill have since recovered and have no more symptoms.

The FBI Buffalo office and the Niagara County Sheriff's office continue to investigate, along with the Niagara County Health Department.