In an on-going US crackdown on Indian call-centre fraud extorting Americans, an American federal judge has sentenced a participant in the scam to seven and a half years in prison.

Judge Virginia Hernandez Covington who sentenced Sharvil Patel, 23, on Thursday in Tampa, Florida, also fined him $80,000.

He was the fourth Indian to be sentenced within two months in the scams where US-based persons worked with operators in Indian call-centres impersonating American tax officials.

Two other Indians belonging to Shravil Patel’s ring were sentenced to prison last month – Nishitkumar Patel, 31, to eight years and nine months, and Hemalkumar Shah, 27, to eight and a half years.

Another Indian, Mehboob Mansurali Charania, was sentenced last month in Atlanta to 16 months in prison and ordered to pay back over $200,000 to his victims.

According to court documents, Sharvil Patel and his accomplices used India-based call-centres to make calls to people in the US pretending to be tax officials from the Internal Revenue Service (IRS) and claiming that they owed taxes threatened the victims with arrest.

They ordered the victims to buy prepaid cash cards and sent people to collect the cards, deposit the payments into bank accounts they opened and turn over the money after deducting a commission, court papers said.

When they were charged last November, officials said that law enforcement officers executed a search warrant at the home of Nishitkumar Patel and seized $50,000 in cash, hundreds of bank and wire transfer receipts, and 20 electronic devices.

Two non-Indians involved in their scam have also been given prison terms.

According to the Treasury Inspector General for Tax Administration Russell George, more than 15,000 victims have suffered over $75 million in losses since October 2013 to telephone scammers impersonating tax officials.

India-linked fraudulent tax extortion through threatening phone calls are rampant.

In October 2016, five Indian companies and 56 people, most of them of Indian descent, were charged in a Texas federal court with involvement in a similar racket.

In October last year, 21 people – at least 20 of them of Indian origin – received sentences ranging between four years and 13 years, with orders of deportation for most of them and revocation of US citizenship of one.