A US grand jury has charged four current and former tax partners of Ernst & Young with tax fraud conspiracy, alleging they marketed fraudulent tax shelters to wealthy clients who would otherwise have owed the Internal Revenue Service more than $10m apiece.

Robert Coplan, Martin Nissenbaum, Richard Shapiro and Brian Vaughn worked in a group set up by E&Y in 1998 to develop and sell tax shelters for the rich. The grand jury alleges that the group, known as Value Ideas Produce Extraordinary Results, or Viper, marketed standardised transactions based on fraudulent “factual” scenarios and falsely told the IRS they were legitimate investments.