Harris County sheriff's officials say initial test results were wrong and flyers found on patrol cars and other vehicles were not tainted with fentanyl.
Authorities said in a statement Friday that an initial test done on a flyer found Tuesday by a sheriff's sergeant who later felt ill resulted in a positive finding for the opioid painkiller known to be more powerful than heroin.
But further testing was later done in a laboratory on 13 flyers, the sergeant's clothing and other samples. All proved negative for the drug.
The sergeant had reported dizziness, impaired vision and other symptoms after removing the flyer from her patrol car. It's not clear what caused her to become ill.
The flyers promoted a group whose website includes claims that the government is controlling individuals through microwave beams.
