The U.S. Department of Justice announced Thursday that criminal charges have been brought against 243 individuals for Medicare fraud totaling $712 million in false health care billings.

The charges were announced following a nationwide sweep by the Medicare Fraud Strike Force in 17 federal judicial districts involving about 900 law enforcement officials, the DOJ said.

Among those arrested are 46 doctors, nurses and other licensed medical professionals who allegedly participated in "Medicare fraud schemes involving approximately $712 million in false billings," the DOJ said in a press release.

Defendants allegedly submitted claims to Medicare and Medicaid for "treatments that were medically unnecessary and often never provided," the DOJ said. Charges include conspiracy to commit health care fraud, violations of the anti-kickback statutes, money laundering and aggravated identity theft; involving home health care, psychotherapy, physical and occupational therapy, durable medical equipment and pharmacy fraud.

Fifty individuals were charged with fraud related to the prescription drug benefit program called Medicare Part D, which is the fastest-growing component of the entire Medicare program.

Attorney General Loretta Lynch described the bust as "the largest criminal health care fraud takedown in the history of the Department of Justice."

"In the days ahead, the Department of Justice will continue our focus on preventing wrongdoing and prosecuting those whose criminal activity drives up medical costs and jeopardizes a system that our citizens trust with their lives. We are prepared - and I am personally determined - to continue working with our federal, state and local partners to bring about the vital progress that all Americans deserve," Lynch said.

One of the most "egregious allegations," according to Lynch, involved owners of a Miami mental health facility who "billed for intensive psychotherapy sessions that resulted in tens of millions in reimbursements for the doctors based on treatment that was nothing more than moving patients to different locations. Several of these patients suffered from illnesses like Alzheimer's and dementia and were unable even to communicate with their supposed caregivers."

Since 2007, Strike Force operations targeting Medicare fraud have resulted in charges against more than 2,300 people who falsely billed the government over $7 billion, the DOJ said.