A North Charleston store owner said she feels like she was robbed by the federal government this week after agents carted off merchandise and “a lot of cash” in a raid tied to a probe of synthetic marijuana sales.

Exchange Factor owner Joan Graf said Drug Enforcement Administration agents visited her vintage clothing store at 5128 Rivers Ave. on Tuesday carrying a search warrant.

Graf said the agents grilled her employees, demanded to know where the money was located, kicked in the door of her adjoining apartment and rummaged through her underwear drawer and belongings. They left with packets of what she calls “botanicals,” computer equipment, $6,000 in money orders and an undetermined, but significant, amount of cash, she said.

“I followed them around while they robbed me, basically,” Graf said. “That’s how it feels anyway.”

Graf, who has been in business 21 years and operates four stores in the Charleston area, said agents told her the raid was connected to a crackdown on fake marijuana. But she said the items she sells are considered “botanicals” that are meant to be used as incense or potpourri, not smoked.

Beth Drake, spokeswoman for the U.S. Attorney’s Office in Columbia, declined to respond to Graf’s statements, saying federal prosecutors do not comment on pending cases.

On Wednesday, U.S. Attorney for South Carolina Bill Nettles confirmed an ongoing investigation aimed at shutting down sales of the potent and potentially dangerous fake pot, also known as K2 and Spice.

Three Charleston area merchants were indicted this month on drug and money-laundering charges in connection with the probe.

Federal and state authorities have moved in recent years to close legal loopholes that allowed sales of the faux pot — herbal mixtures sprayed with a stew of chemicals that mimic marijuana’s main active ingredient, THC — to creep into corner stores and other outlets.

Just this month, the DEA made three more chemical strains of synthetic marijuana temporarily illegal under the federal Controlled Substances Act “to avoid an imminent hazard to the public safety.”

Graf said she pays close attention to such changes to make sure she is in compliance with the law. The merchandise seized this week arrived through the mail from a company in California, and none of the packets contained chemicals that have been outlawed by the federal or state governments, she said.

“Mine is not on the banned list,” she said.

Graf said she would never intentionally sell a product that would hurt customers and she won’t sell botanicals to people who say they plan to smoke or otherwise ingest it. “We’re very hard-core about that,” she said.

Federal and state leaders have become increasingly concerned about sales and possible abuse of the fake pot, particularly since there is no quality control on production and no guarantees about the potency or safety of the products.

“It’s hit or miss,” Thomas Nuse, assistant special agent in charge of operations with the DEA in South Carolina, said. “You never truly know what you’re getting.”

According to the National Institute on Drug Abuse, synthetic marijuana has become the second-most-popular illegal drug among teenagers, landing more than 11,000 teens in the emergency room in 2010 with symptoms that included vomiting, racing heartbeat, elevated blood pressure, seizures or hallucinations.

But Richard Ward, 32, of Charleston, insists there are some benefits to using the fake pot. Ward said he has severe digestive tract ailments that leave him with chronic pain. He is prescribed pain medication but his system is too sensitive to handle it. The fake pot gave him a legal way to bridge that gap, he said.

“There is another side of this,” he said.

That may be, but he won’t be able to buy it in Graf’s store any time soon. The feds took her existing supply and she turned away another shipment that was to arrive Thursday, not wanting to draw more federal attention.

“I’m not going to poke the snake that just bit me,” she said.

Reach Glenn Smith at 937-5556 or Twitter.com/glennsmith5.