Authorities are zeroing in on a farm in southwestern Indiana, although they are not revealing its name.
The farm has withdrawn its product and will not ship cantaloupes for the rest of the season.
The Centers for Disease Control and Prevention is warning consumers to throw out any cantaloupe from southwest Indiana.
Wal-Mart has announced it is voluntarily pulling all cantaloupe from Indiana from store shelves.
The outbreak began in early July and has spread to 20 states.
