As many as 15 people, including seven Indians, and five India-based call centres have been indicted in a multimillion-dollar scam which defrauded over 2,000 US citizens, resulting in over USD 5.5 million in losses, the Department of Justice said on Friday.

The scam involved call centre operators who called potential victims while impersonating officials from the Internal Revenue Service (IRS) or individuals offering payday loans, US Attorney Byung J Pak said.

Later, they threatened victims with arrest, imprisonment, or fines for failing to pay taxes or penalties to the government, the Justice Department said in a statement.

In connection with the scheme, seven individuals were arrested on Thursday in the United States.

Seven co-conspirators and five call-centres based in Ahmedabad were also charged for their alleged involvement.

The indictment alleges that the defendents were involved in a sophisticated scheme organised by co-conspirators in India, including a network of call centres in Ahmedabad.

"IRS and payday loan phone schemes seek to profit by exploiting United States citizens, including the most vulnerable members of our community, said the US Attorney.

"This indictment and yesterday's arrests demonstrate our commitment to identifying and prosecuting those who hide behind these types of phone scams," Pak said.

This indictment makes clear that the IRS impersonation scam has risen to a new level, with indictments against five call centres and seven co-conspirators in India who allegedly directed their employees to participate in the scam, said J Russell George, Treasury Inspector General for Tax Administration.

"I wish to congratulate my investigative team, who labored many long hours to untangle the intricate web of financial transactions that the defendants allegedly completed as part of a transnational conspiracy to extort money from taxpayers and conceal and disguise the proceeds of their unlawful activities."

Between 2012 and 2016, the defendants perpetrated a complex fraud and money laundering scheme in which individuals from call centres located in Ahmedabad frequently impersonated officials from the IRS or US Citizenship and Immigration Services (USCIS) in a ruse designed to defraud victims located throughout America.

The Indian call centres used various telephone fraud schemes to defraud mainly vulnerable Americans, including the elderly and legal immigrants.

Using information obtained from data brokers and other sources, call centre operators allegedly called potential victims while impersonating officials from the IRS or individuals offering fictitious payday loans.

The call centre operators would then threaten potential victims with arrest, imprisonment, or fines if they did not pay taxes or penalties to the government, the indictment alleges.

If the victims agreed to pay, the call centres allegedly would immediately turn to a network of US-based co-conspirators to liquidate and launder the extorted funds by purchasing prepaid debit cards or through wire transfers, including through MoneyGram and Western Union, to the attention of fictitious names and US-based defendants and their co-conspirators, it said.

The five India-based call centres that have been indicted are Excellent Solutions BPO, ADN Infotech Pvt Ltd, Infoace BPO Solutions Pvt Ltd, Adore Infosource, Inc and Zurik BPO Services Pvt Ltd.

The 15 individuals who have been charged are Shylesh Kumar Sharma, Dilipkumar Kodwini, Radhishraj Natarajan, Shubham Sharma, Nirav Janakbhai Panchal, Athar Parvez Mansuri, Mohmmad Samir Memon, Mohamed Kazim Momin, Palak Kumar Patel, Mohmed Sozab Momin, Rodrigo Leon-Castillo, Devin Bradford Pope, Nicholas Alezander Deane, Drue Kyle Riggins and Jantz Parrish Miller.

Mohamed Kazim Momin, Patel, Mohmed Sozab Momin, Pope, Deane, Riggins and Miller were arraigned yesterday before US Magistrate Judge Janet F King.