AUSTIN, Texas — Three men have been arrested and a fourth person is sought in what federal authorities say was an Austin-based stolen identity fraud scheme that filed fraudulent income tax returns seeking more than $3 million in refunds.

According to a 10-count indictment unsealed Wednesday, the defendants collected more than $630,000 in refunds and nearly $17,000 in bogus credit card transactions.

Federal authorities say they arrested 54-year-old Nigerian national George Najomo in Austin and two Sudanese nationals, 36-year-old Ibrahim Alu and 40-year-old George Ismail, in Grand Prairie, outside Dallas. A warrant has been issued for 44-year-old Nigerian national Dele Akanbi.

According to the indictment, the four operated an Austin cleaning business, stole patient forms and documents from medical facilities and used that information to file phony tax returns and obtain credit cards.