A Bulgarian citizen who admitted his role in a $6 million fraudulent tax return scheme has been sentenced in New Jersey to nearly four years in prison.

Vanyo Minkov was part of a ring that used personal information stolen from accounting firm networks. He was sentenced Thursday after pleading guilty last July to conspiring to file false and fraudulent tax returns.

Prosecutors say in 2012, the conspirators hacked into the networks of at least four accounting firms and stole the 2011 tax filings for more than 1,000 clients. They used the information to file fraudulent returns or sold the information to others for the same purpose.

The IRS has identified more than $6 million in fraudulent claims made in the scheme.

Minkov was also ordered to pay $2,700 in restitution.