According to the Bloomberg report, 25 of the 95 prosecutors in the tax division have left the Washington headquarters for six-month, whereas another three have taken permanent assignments.
The transfers came amid criminal probes of at least 11 Swiss financial institutions, with the tax division leading or assisting each prosecution.
The publication quoted Nathan Hochman, a former assistant attorney general who oversaw the tax division under President George W. Bush, saying to move one-third of these people from that effort will significantly compromise such enforcement at the very time it is needed to deal with the huge amounts of offshore cases coming to the tax division.
The tax division looks into identify theft, illegal tax shelters and other crimes, while approving every tax case filed by the 94 presidentially appointed US attorneys serving the Justice Department around the country.
Ever since the offshore tax crackdown has expanded since 2007, prosecutors have filed criminal charges against at least 21 foreign bankers, advisers and attorneys and at least 40 US taxpayers.