A New Zealand investment banker has been jailed after spending millions of dollars of clients money on prostitutes.

The man, Stephen Versalko, 51, has been sentenced to six years in prison for stealing nearly US$14 million.

The crimes which took place over a nine year period, only came to light when one of Versalko's wealthy victims saw a television documentary on convicted New York fraudster Bernard Madoff.

Police investigated after the victim's suspicions were raised and it was found Versalko had spent clients money on prostitutes, wine, property and making interest payments to keep the Ponzi-like scheme running.

A large amount of money went to a prostitute who started blackmailing Versalko.