A Canadian doctor has been arrested in what U.S. officials say is a massive case of health-care fraud, allegedly worth nearly US$375 million.

The charges against Dr. Jacques Roy, 54, and six others were revealed Tuesday in Dallas, Tx. by Deputy Attorney General James Cole.

He alleged that Roy's practice, located in Desoto, Tx., fraudulently signed up thousands of people for government health benefits over a five-year period.

"Medistat is alleged to have certified more than 11,000 Medicare beneficiaries for home health services provided by more than 500 home health care agencies, or HHAs," said Cole.

"In turn, these HHAs and Medistat are alleged to have fraudulently billed Medicare for more than $350 million, and Medicaid for more than $24 million."

Although Roy's practice includes just four doctors and 15 nurses, it is alleged to have certified more Medicare beneficiaries for home health services, and had more beneficiaries under its care than any other medical practice in the U.S.

Cole said the investigation was carried out by the federal Medicare Fraud Strike Forces -- teams run by the Justice Department and U.S. Attorneys' Offices with the goal of eliminating healthcare fraud.

A memorandum filed in a Texas court on Feb. 28 argued that Roy was a flight risk and should be detained pending trial. The memo calls him the "mastermind" of the operation and said he faced a likely life sentence if convicted on the "strong" evidence against him.

"And perhaps most importantly, Dr. Roy has created a false identity and squirreled away millions of dollars of assets that likely would be available to him should he choose to flee," states the memorandum.

The document alleges Roy worked with home health agencies that went door-to-door recruiting patients for services, then signing them up regardless of whether or not they needed care.

Roy or another physician at his Medistat practice would then certify the patient for services, for which the home health agency could then bill Medicare.

Every patient they recruited was also added to Medistat's patient roster "so that Medistat could bill Medicare for more unnecessary services associated with that patient," the memo alleged.

After searching Dr. Roy's home in Rockwall, Tx., investigators found evidence he had created a fake identity in the name of "Michel Poulin," and had a Texas driver's license, Canadian birth certificate, and Canadian passport application in the name of Poulin, among numerous other identity documents in Poulin's name.

Investigators also found correspondence with numerous offshore banks and a KPMG guide to ship and yacht registration in the Cayman Islands and a copy of Edmund J. Pankau's "Hide your A$$etS and Disappear: A Step-by-Step Guide to Vanishing Without a Trace."

None of the charges against Roy have been proven in a court of law. Roy's lawyer said his client maintains his innocence.