MIAMI (CBS4)- Federal authorities are calling it the largest international Medicare fraud bust to date.

The arrests out of Bogota, Colombia, Monday follow a joint investigation in November, 2009, into Medicare fraud by the CBS4 I-Team and CBS’s newsmagazine 60 MINUTES.

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CBS4  I-Team investigator Stephen Stock has the story of how investigators from the US Department of Health and Human Services finally caught up to two international fugitives wanted scamming Medicare out of millions.

If you weren’t looking closely, you might have thought they were tourists returning to Miami from overseas.

Instead, shortly after midnight, early Tuesday morning, March 15, 2011, 54 year-old Caridad Guilarte was escorted in handcuffs by federal agents off Avianca Airlines flight number 8 out of Bogota, Colombia. Caridad was followed closely behind by her 56 year-old sister Clara, also in handcuffs.

Federal agents say both women had been hiding out in Bogota after being indicted on 11 different federal counts charging them with running a Medicare fraud scheme out of Dearborn, Michigan, near Detroit.

According to the federal indictment, it was a scheme that requested $9,122,159.35 in fraudulent Medicare claims. And the indictment charges that the scheme landed the sisters $4,275,799.75 in actual Medicare payments, taxpayer dollars they weren’t due.

Guilarte Sisters Indictment

Gerald Roy is the Deputy Inspector General at the Department of Health and Human Services…

Deputy Inspector General Roy said the arrests of the Guilarte sisters shows federal investigators will span the globe to seek justice for those who steal from Medicare.

“We have a global reach and we certainly will find you,” said Roy.

“We’re sending a message here that if you steal from Medicare and if you abscond with our money and think you can hide out in a foreign country you’d better think again,” said Roy.

Roy spoke to the CBS4 I-Team from Washington, D.C. after the Guilarte sisters were brought back to the US through Miami International Airport early in the morning.

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“What they did was they brought in Medicare beneficiaries and paid those beneficiaries anywhere from $50 to $100 for their Medicare number,” said Roy. “And those beneficiaries received infusion therapy. These are invasive services with no medical necessity.”

According to Florida Department of State business records obtained by the I-Team, the Guilarte sisters actually started by setting up medical clinics in Miami and Orlando.

Federal authorities have long said that South Florida spawns various Medicare fraud schemes. Schemes that are tried out here then, if successful, they are exported by those who would commit fraud to cities around the country such as Detroit.

“They (Medicare fraud schemes are) tested here and funnel out to different parts of the country,” said special agent Omar Perez. “(Detroit, Houston, Baton Rouge and) Los Angeles are seeing some of same schemes (as South Florida.)”

Special agent Omar Perez is with the US Department of Health and Human Services Office of Inspector General Office of Investigations.

Perez helps run the Medicare fraud task force here in South Florida and says the fraud schemes developed here, like the ones allegedly run by the Guilarte sisters, are then transplanted to cities across the country, such as outside Detroit where the sisters ended up.

“South Florida is ground zero,” said Perez. “It’s where (the fraud schemes) are developed, where (they are) tested, and once (the schemes are) proven (then) ships out to other parts of the country.”

“These schemes spread from area to area,” said Gerald Roy. “The Guilarte sisters, for example, started their scheme in South Florida and saw fertile ground and a new beneficiary core up in the Dearborn, Michigan, area and decided to move their base of operations to that particular area.”

This was the largest international Medicare fraud bust to result from a tip generated by a brand new top ten fugitive website established and run by HHS.

Click here to go to HHS’ Top Ten Fugitive website

The fugitive website is devoted only to people charged with Medicare fraud who are still at large. Many if not most of those on the website are believed to have fled the country and are hiding out overseas.

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The website has been active only since February. but in that time, HHS officials say it has already generated more than 60,000 hits.