The founder of the online gambling site, BetOnSports, which operated in the Caribbean, has been sentenced to more than four years in prison.

Gary Kaplan has pleaded guilty to various charges of fraud and racketeering related to his company.

In addition to the four year jail sentence, he has been ordered to forfeit over US$43 million in illicit earnings.

BetOnSports, with bases in countries such as Aruba, Antigua and the Dominican Republic, encouraged American gamblers to place bets online, a practice that's illegal in the US.

Prosecutors have alleged that 50-year-old Kaplan still has millions of dollars in Swiss bank accounts.