Amtrak OIG agents support nationwide action to combat alleged COVID-19 health care fraud

April 25, 2023 |  Investigations Press Release

For Immediate Release

April 25, 2023

LOS ANGELES – Agents from the Amtrak Office of Inspector General supported a nationwide law enforcement action April 12, 2023, that resulted in criminal charges against 18 defendants for their alleged participation in fraud schemes that exploited the COVID-19 pandemic, resulting in more than $490 million in false billings to federal programs and theft from federally funded pandemic programs.


The entirety of the Department of Justice-led operation spanned nine federal districts in six states and one U.S. territory. More than $16 million in cash and other assets were seized as a result of the operation. Of the 18 defendants charged, seven were licensed medical professionals.


Amtrak OIG agents supported search warrant operations in California in the investigation of Dr. Anthony Hao Dinh, 63, of Orange County, California. Dinh was charged by complaint for allegedly orchestrating an approximately $230 million fraud on the Health Resources and Services Administration Uninsured Program. According to a case summary on the DOJ’s website, Dinh was the second highest biller in the country to the Uninsured Program, and he allegedly submitted fraudulent claims for treatment of patients that were insured, billed for services not rendered, and billed for services not medically necessary.


Dinh allegedly used over $100 million in fraud proceeds to engage in high-risk options trading. Dinh is also charged with two other individuals, Hanna T. Dinh, also known as Hang T. Dinh, 64, also of Orange County, California, and Dr. Matthew Ho, 65, of Brevard County, Florida, for allegedly submitting over 70 fraudulent loan applications under the Paycheck Protection Program and Economic Injury Disaster Loan Program and fraudulently obtaining over $3 million in loan funds.


In addition to the Amtrak Office of Inspector General, the enforcement action was supported by the FBI; Health and Human Services OIG; the Small Business Administration OIG; Defense Criminal Investigative Service; IRS Criminal Investigation; Department of Treasury Inspector General for Tax Administration; Department of Homeland Security OIG; California Department of Health Care Services; and other federal and state law enforcement agencies. A summary of criminal charges resulting from the enforcement action can be found online at


Reports of fraud, waste, or abuse; criminal or unethical acts affecting Amtrak’s property or operations; or mismanagement in Amtrak programs or operations can be made 24 hours a day via the Amtrak OIG Hotline at 1-800-468-5469 or online at



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