U.S. House Committee on Oversight and Reform ranking member James Comer (R-Ky.) has sent letters to chairman and chief executive officer of the Alibaba Group, Daniel Yong Zhang, and president and CEO of eBay Inc., Jamie Iannone.

In the letters, he expressed concerns regarding their platforms allowing the sale and importation of foreign plant and animal products into the United States. Thousands of Americans have received unsolicited seed packages. In response, Comer asked the companies what steps they’re taking to prevent the unlawful distribution of foreign seed products that could be designed to harm U.S. agriculture production, the environment, and the economy.

“When mystery seeds from China began landing in Americans’ mailboxes, we knew we had a problem,” Kentucky’s First District Congressman said. “State and federal agricultural officials promptly warned the public that these products, when planted, pose enormous risks to U.S. agriculture. An invasive plant species could wreak havoc and introduce unknown diseases to our local crops, livestock or ecosystem.

“In order to protect Americans, it is crucial for companies and their platforms to abide by U.S. customs laws, which rightfully prohibit sellers abroad from importing seeds. In the wake of these China seeds, Amazon took a common sense approach to protecting American agriculture by no longer allowing their distribution on their site. Now, it is time for eBay and the Alibaba Group to commit to the same.”

In conjunction with the U.S. Department of Agriculture, Amazon Services recently announced it will prohibit both the importation of plant or seed products into the United States and the listing or sale of plant-based products by non-U.S. residents.

Comer called on eBay and Alibaba to ensure they are taking similar steps in order to reduce the risk of Americans receiving unsolicited seed packages and to further protect U.S. agriculture.