EAST HARLEM (WABC) -- There is one less medical clinic operating in East Harlem, and that may be a good thing for taxpayers. Following an Eyewitness News alert to the Attorney General's Office, the facility was shut down, suspected of Medicaid fraud.Police from the Attorney General's Medicaid Fraud Unit moved in on the clinic Tuesday morning, seizing medical billing records, equipment and files.For weeks prior to the raid, Eyewitness News had been investigating the clinic. Using a hidden camera, we went undercover to see whether poor people, desperate to make a little money, were turning over their Medicaid cards. In the wrong hands, experts say they are as good as cash."Is this the place where they are doing the Medicaid?""The $30?""Yeah.""Yeah, right here." (points to office)We spent days undercover observing several hawkers, or patient recruiters, approaching people outside the medical clinic and offering them $30 cash to see their Medicaid card.When someone handed over his or her card, the recruiter would then text or email the information to someone inside the clinic. One woman entered the clinic after giving her card to one of the recruiters, and after spending less than 10 minutes inside, she came back out. Seconds later, one of the hawkers handed her an envelope.After observing this same scenario play out numerous times over several days, we sent an undercover Medicaid cardholder to walk by the clinic to see if he would get approached. He did, immediately."You on Medicaid?""Yeah.""I'll give you $30 right now if you take a physical.""For what?""For a physical, $30.""For my Medicaid?""Yeah, what plan you got?"The recruiter told our perfectly-healthy undercover person that a real quick check inside would get him $30 cash."I'll check you out right now," he said. "If your card come back good, you go in there, you do a physical, and then you get $30. Don't tell them nothing about the money. You deal with me about the money."Our undercover guy never gave him the information and instead walked away, but plenty of people did for a quick $30. Some of the incidents played out practically in front of the police, and the boldness of the operation surprised former Medicaid fraud investigator William McGoldrick."The volume and the way that they are accosting people on the street, that's not legitimate practice, in any kind of medical provider," he said. "They will take any opportunity they can to get the Medicaid card and provider recipient number that goes with it. That's like gold to them. They can use it over and over again."And for days, we watched as the patient recruiters outside the clinic got Medicaid card information for a quick $30, week after week in an operation that could be costing taxpayers a fortune in medical charges that authorities say were either not needed or never provided.We alerted law enforcement to our findings two weeks ago, and they launched their own investigation that resulted in the raid and the closing down of the clinic."They could be running up prescriptions, they could be running up any number of tests," McGoldrick said. "They are very expensive."Eyewitness News had been watching the clinic since early September, and when the AG's Medicaid Fraud Unit showed up, it brought a small army of at least 15 police officers. They spent hours tagging and organizing hundreds, possibly thousands, of patient records that were hauled off as evidence in what we are told is an expanding investigation.