Officials with the U.S. Department of Agriculture (USDA) and the Better Business Bureau say packages of mystery seeds showing up in mailboxes may be part of what's known as a "brushing" scam.

Anybody who gets one of the unsolicited packages containing seeds believed to have come from China and neighboring Kyrgyzstan should not plant them. And then it would be wise to check their bank accounts, credit card statements and credit reports, said Bao Vang with the Better Business Bureau of Minnesota and North Dakota.

Vang said such unsolicited packages, sometimes labeled as containing jewelry, small electronics or other items, are used in the scams to boost products' ratings in online marketplaces.

It works like this: A third-party seller finds addresses online and sends an unsolicited item, like the seeds. The seller then writes a glowing review of its own merchandise online, using evidence of the mailed package to claim that the reviewer is a verified buyer. The positive review is meant to improve a products' rating and sales, Vang said.

Receiving such a package could be a sign that an individual's personal information has been compromised, she said.

Candy Conniff got one of the packages at her home in Silver Lake, Minn., on Thursday. She said her seeds looked like acorn squash. But without being sure, there was no way she was going to plant them in her large vegetable and flower gardens at her home about 60 miles west of the Twin Cities.

"I put them back in the package and taped it shut," she said.

But it makes her nervous that somebody might have her personal information.

"It's spooky," she said. "It came with my full address and phone number on it."

As of Friday, more than 700 Minnesotans had contacted the Minnesota Department of Agriculture's Arrest the Pest Line at 1-888-545-6684 to report they had received packages of seeds, said spokesman Allen Sommerfeld.

The department said in a statement Friday that it has identified some of the seeds as cosmos, radish, mung bean, juniper, basil, cucurbit, and zinnia. While these are not seeds from invasive plants, seeds may carry disease and pests can hide in packaging.

The state agriculture department has also set up an e-mail,, for submitting information about packages received.

USDA is collecting the seed packages and will test their contents to determine if they contain anything that could be of concern to U.S. agriculture or the environment, said Osama El-Lissy, with the Plant Protection program of USDA's Animal and Plant Health Inspection Service.