WASHINGTON (CNN) -- The federal government recovered almost $4.1 billion stolen in health care fraud schemes during fiscal year 2011, Obama administration officials announced Tuesday. The figure is up 58 percent from 2009.

"This is an unprecedented achievement -- and it represents the highest amount ever recovered in a single year," said Attorney General Eric Holder. The Justice Department reported more than 1,400 people were charged with fraud in 500 cases. There have been more than 700 convictions.

"We're regaining the upper hand in our fight against health care fraud," said Health and Human Services Secretary Kathleen Sebelius.

The numbers are contained in the Health Care Fraud and Abuse Control Program Annual Report, which is sent to Congress.

Holder and Sebelius credited their Medicare Fraud Strike Force teams for tracking down crime in areas with "hot spots" of unexplained Medicare billing. The strike forces include prosecutors and investigators from the FBI, the Justice Department and the Health and Human Services Office of Inspector General.

In fiscal year 2011, new teams were created in Dallas and Chicago. They joined seven existing groups in Miami; Los Angeles; Detroit; Houston; Baton Rouge, Louisiana; Tampa, Florida; and the Brooklyn borough of New York.

Holder said recently strike forces have handled two large, multiple-city fraud takedowns. In one case, 115 people were arrested in nine cities for alleged false billing schemes amounting to more than $240 million. A second case involved $290 million in allegedly fraudulent bills in which 91 defendants were charged in eight cities.

Health care fraud has attracted both organized crime organizations and street gangs, according to Kevin Perkins, the FBI's assistant director for the Criminal Investigative Division.

Perkins said that through computer analysis the FBI can look at many thousands of Explanation of Benefit forms and detect hot spots showing excessive Medicare billing, which law enforcement can then pursue.

"We're making an impact," Perkins said.

Officials say fraudulent schemes include illegal marketing of medical devices and pharmaceuticals for purposes not approved by the Food and Drug Administration, Medicare fraud by hospitals and other institutional providers, illegal pricing by makers of drugs, and violations of laws against self-referrals and kickbacks.

Sebelius said aggressively pursuing health care fraud is a great investment.

"Over the last three years, for every dollar we've spent, we've put more than seven dollars back in the hands of American taxpayers," she said. The money goes into the Medicare Trust Fund, the U.S. Treasury and state treasuries.

Officials said the Affordable Care Act helps in the fight against fraud in various ways, including providing $350 million in resources, increasing data sharing, and expanding efforts to get money back after overpayments.