A 71-year-old retired business school professor who pleaded guilty co concealing hundreds of millions of dollars from US authorities has been handed a seven-month jail sentence and slapped with a multitude of fines.

A former client of Credit Suisse who pleaded guilty to concealing $200 million from US tax authorities was last week sentenced to seven months' imprisonment and ordered to pay fines totalling more than $113 million.

Dan Horsky, a 71-year-old retired business school professor, stashed $220 million in secret foreign accounts for 15 years and consequently evaded more than $18 million in income and gift tax liabilities, the US Department of Justice said.

Horsky was also sentenced to a year of probation, 50 hours of community service and fined $250,000 last week in federal court in Alexandria, Virginia. As part of his plea agreement, he paid a penalty of $100 million to the US Treasury for failing to file, and filing false, foreign bank account reports and paid more than $13 million in taxes owed to Internal Revenue Service.

“Horsky went to great lengths to hide assets overseas in order to avoid paying his share of taxes to the IRS,” US attorney Dana Boente said in a statement. 

Prosecutors urged a judge to jail Horsky for 20 months, a far lower sentence compared with federal guidelines of 57 to 71 months. Judges are not bound by the guidelines, however. 

Horsky's lawyers said he deserved probation because he cooperated with investigations and will pay a plethora of hefty fines.

Horsky's tax evasion scheme came to a close when IRS special agents knocked on his door. 

“The days of hiding behind shell corporations and foreign bank secrecy laws are over,” said deputy assistant attorney general Stuart Goldberg.

He added: “Now is the time for account holders to come in, accept responsibility, and help ensure that the lawyers, financial advisors and other professionals who actively facilitated offshore evasion also are held accountable.”