Bhavesh Patel, 47, from Arizona and Asmitaben Patel, 34, from Illinois pleaded guilty to conspiracy to commit fraud and money laundering offenses, the Department of Justice said.
Sentencing dates are pending.
A total of eleven defendants have plead guilty thus far in this case.
Co-defendants Bharatkumar Patel, Ashvinbhai Chaudhari, Harsh Patel, Nilam Parikh, Hardik Patel, Rajubhai Patel, Viraj Patel, Dilipkumar A Patel and Fahad Ali previously pleaded guilty on various dates between April and June.
Using information obtained from data brokers and other sources, call center operators targeted US victims who were threatened with arrest, imprisonment, fines or deportation if they did not pay alleged monies owed to the government.
Victims who agreed to pay the scammers were instructed how to provide payment, including by purchasing stored value cards or wiring money.
Upon payment, the call centers would immediately turn to a network of "runners" based in the US to liquidate and launder the fraudulently-obtained funds, federal investigators alleged.