The U.S. Justice Department’s abandoning of a 2011 opinion that had permitted certain forms of internet gambling drew a legal challenge Friday from an online lottery company, which said the government’s abrupt reversal was “deeply flawed” and the product of a lobbying campaign by a prominent Las Vegas casino magnate.

The company, NeoPollard Interactive LLC, represented by the law firm Gibson, Dunn & Crutcher, filed the lawsuit in U.S. District Court for the District of New Hampshire. The New Hampshire Lottery Commission, represented by the state attorney general’s office, filed a related challenge against the Justice Department. NeoPollard serves as the technology and service provider of the New Hampshire state iLottery system.