On Monday, the DoJ reversed its September 2011 opinion, which interpreted the Wire Act as legislation which only applies to sports betting.

The law was formed in 1961 and prohibits all interstate wagers placed – or information passed on pertaining to wagers – via telephone or wired communication facility.

But, in its new opinion, the DoJ has judged the Wire Act to be applicable to all forms of gambling – including online casino, poker and lottery.

On Tuesday, outgoing Deputy Attorney General, Rod Rosenstein, issued a memo that the 90-day delay will allow operators to adjust, according to the Associated Press.

However, it remains unclear exactly how the DoJ will implement the new ruling, as legal experts say casino operators and online lotteries will contest the issue in court.

Becky Harris, the outgoing Chair of the Nevada Gaming Control Board, is also quoted as saying: "There is an interstate compact between Nevada, Delaware and New Jersey, where Nevada participates with regard to poker only, and that’s [now] in question."