"It's quite amazing how high the criminal energy can be, but we are quite confident that the [Division of Gaming Enforcement] will shut that down quite efficiently and soon," said Teufelberger, whose Gibraltar firm is partnered with Borgata in New Jersey.
The state Division of Gaming Enforcement confirmed it was "aware of this issue and is taking steps to coordinate an appropriate response to this illegal activity," said Kerry Langan, a spokeswoman.
Asked for details, Langan said only that "the illegal activity is offshore companies offering online gaming to New Jersey residents without licensing or approval" by authorities.
John Shepherd, a spokesman for Bwin.Party, said Friday the federal Unlawful Internet Gambling Enforcement Act of 2006 did not stop all overseas companies from allowing people in the United States to gamble online.
"It's only companies like ourselves that switched off," Shepherd said.
The legalization of Internet gambling in New Jersey made people aware they could play poker and other casino games online, Shepherd said.
Though New Jersey gambling regulators have authorized 16 websites that must be associated with Atlantic City casinos to offer online gambling, it's unlikely consumers are familiar with the list.
"That gives an opportunity for the illegal sites to target people in New Jersey who would probably be unaware that they are playing on illegal sites," Shepherd said.