Walmart is recalling certain Great Value brand frozen shrimp after the FDA warned of possible radioactive contamination.

The shrimp, imported from Indonesian supplier PT. Bahari Makmur Sejati, may contain Cesium-137, though no recalled products have tested positive.

Walmart has pulled the items from stores, urged customers not to eat them, and is offering refunds, CBS News has reported.

The FDA said the warning followed detection of Cesium-137 in one shipment from the supplier that never reached U.S. consumers.