PHILADELPHIA — A personal trainer from Phillipsburg fraudulently obtained steroids and then sold them over the Internet, authorities allege.

An indictment unsealed Wednesday charges Eric C. Opitz, 45, with 10 counts of health care fraud, three counts of mail fraud, and seven counts of illegal distribution human growth hormones and anabolic steroids.

READ THE INDICTMENT

Opitz used used Medicare Part D benefits to obtain the drugs, United States Attorney for Eastern Pennsylvania Zane David Memeger said. Opitz received the HGH and anabolic steroids at no cost by claiming that a $950 per month social security payout was his only source of income, authorities said.

Although Opitz is 6-foot-3, 450 pounds, he was prescribed HGH for the treatment of pituitary dwarfism, court papers say. Children with that condition typically have growth problems and don't reach 5 foot by the time they're adults.

Prosecutors allege Opitz typically sold 5 mg "kits" of HGH for $450 and charged more for larger amounts. He used Craigslist to make sales, according to the indictment.

Authorities gather evidence against Opitz after he allegedly made several sales to undercover federal agents.

Medicare, meanwhile, paid $535,518 to obtain to the drugs for Opitz from January 2011 to June 2014.

He faces a "substantial term of imprisonment" if convicted, authorities said.

Jeff Goldman may be reached at jeff_goldman@njadvancemedia.com. Follow him on Twitter @JGoldmanNJ. Find NJ.com on Facebook.