Washington (CNN) -- The U.S. Department of Agriculture has issued a warning to be on the lookout for unsolicited fraudulent faxes made to look like they're coming from a USDA official.
At least a dozen individuals and businesses in Alabama, Nebraska, Pennsylvania and Wisconsin have reported receiving faxed documents, prompting a federal investigation.
Officials say the letters appear to be sent by USDA Senior Procurement Officer "Frank Rutenberg," complete with USDA logo and seal.
But the USDA says it has no record of an employee by that name and the position of Senior Procurement Officer does not exist. According to the department, the documents ask the recipient for their bank information, phone numbers, tax information and a signature giving approval to perform a background check.
A government warning was initially issued on Friday, but since then officials say more fraudulent faxes have been reported, including the latest which was reported Tuesday.
In a statement on its website, the USDA says the letters are "false and in no case should a recipient respond with personal and financial information."
The USDA says the Office of Inspector General is investigating.