Washington -  The Treasury Department has arrested five people in Miami accused of posing as IRS agents in telephone calls and demanding immediate payment of overdue taxes, a scheme that netted them an estimated $2 million, a top official said Tuesday.

J. Russell George, who heads the Treasury Inspector General for Tax Administration office, said Tuesday that the five defrauded about 1,500 people.

The IRS has called similar impersonators the largest such scam in agency history. George said overall, 1.2 million Americans have reported receiving such calls, and around 6,400 of them have reported being cheated out of $36.5 million.

The callers pose as IRS or Treasury agents and demand immediate payment of back taxes or other fees, threatening arrest if they don’t. George said some scammers demand that people pay using iTunes or other prepaid debit cards.... Read More: VIN