Taxpayers are paying for thousands of homebound people to receive unnecessary diabetic treatments, The Miami Herald reported Sunday. Many patients for which the government is being billed either don't have the disease or don't need a visiting nurse to inject insulin, the newspaper said.

Medicare's average annual expense for a homecare patient is $19,230 in Miami-Dade County, or 164 percent more than in Los Angeles and 91 percent more than in Dallas.

"I would have to attribute a lot of this activity to fraud to extract money from the system," said Jeff Gregg, a senior regulatory official at the Florida Agency for Health Care Administration, which licenses Medicare and Medicaid providers. "As far as I can see, there is no other plausible explanation."

Randall Culp, an FBI special agent who works with the Medicare Fraud Strike Force in Miami, said there are "black and white fraud cases out there," such as when home healthcare agencies file false claims for services that were not provided.

"'We need to focus on the fraudsters so the legitimate patients can continue to receive these services," Miami U.S. Attorney Alexander Acosta said.