MARTIN COUNTY — Thieves have been hitting convenience stores in Martin County, authorities said, stealing a herbal supplement connected with a series of overdose deaths.

The Martin County Sheriff's Office is trying to find a man and a woman who stole liquid kratom from three stores during the last several days. Friday, detectives released surveillance photos of the suspects from a Thursday morning theft.

The couple was driving a late model four-door car, the Sheriff's Office said.

Kratom is a legal supplement that at low doses causes a stimulant effect. At higher doses, it causes an opioid-like effect, which can produce an intense euphoric state and has led to a steady growth in abuse worldwide, experts said.

But it can also cause seizures, decreased breathing and, at times, death. The Food and Drug Administration and Drug Enforcement Administration warn against its use.

For the first five months of this year, eight overdose deaths were linked to the herb on the Treasure Coast, including an inmate at the Indian River County Jail. Last year, nine deaths were linked to kratom.

Anyone with information about the shoplifting, call the Martin County Sheriff’s Office at 772-220-7060.

More:Hobe Sound man accused of making hash oil and pushing grandmother to ground

More:Treasure Coast sees increase in kratom-involved deaths, Medical Examiner's Office says

Stancil is a breaking news reporter for FLORIDA TODAY and TCPalm.

Contact Stancil at 321-242-3662 or 321-987-7179

or lamaur.stancil@tcpalm.com.

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