TRENTON, N.J. — A lobbying group and New Jersey hunters want a federal judge to overturn a new law that makes it illegal to import or export big-game trophies of threatened or endangered animals.

Conservation Force and a group of hunters filed a federal lawsuit Friday, seeking to have the law signed last month by Republican Gov. Chris Christie voided. The suit says lawmakers ignored federal regulations governing trophy hunting.

Lawmakers approved the measure in response to the killing last year of Cecil, a Zimbabwean lion, by a Minnesota dentist. The killing caused an international uproar and shed a spotlight on trophy hunting, and airlines including Atlanta-based Delta Air Lines and Chicago-based United Airlines last year banned transporting parts from animals killed in hunts.

Conservation Force says in the lawsuit that licensed, regulated, tourist safari hunting is an essential component of conservation programs and helps fund operations that safeguard wildlife habitats and fight poaching in Africa. The U.S. Fish and Wildlife Service regulates the import of trophy animals, requiring that hunters get permits and that the animals be killed as part of hunts based on a science-based conservation strategy that enhances the species in the wild.

Democratic state Sen. Raymond Lesniak, who sponsored the measure, said he doesn’t believe there’s anything in the federal regulation to pre-empt the state law and he hopes other states will adopt the bans.

“They have a monetary interest at stake here, and the public has a humane interest,” he said of the group filing the lawsuit. “I expect the humane interest will prevail.”

John Jackson, president of the Louisiana-based Conservation Force, said he doubts New Jersey would be able to regulate the ban, but it’s important for hunters to invalidate it.

“It’s just what we call a placebo to make people feel good. It costs more to implement than it’s ever worth,” he said.

The lawsuit names acting state Attorney General Christopher Porrino and Department of Environmental Protection Commissioner Bob Martin as defendants. Spokesmen for both agencies said they had no comment.

Robert Viden Jr., one of the hunters involved with the suit, said in a filing that the money he has spent on big-game safari hunts has gone to support rural people in Africa and help “reduce the conflict between people and wildlife.”

“A trophy is a critical part of the hunt. It represents the experience, the game, and my love for the sport,” Viden said, noting that he hopes to return to Africa for a hunt soon with his grandson. “If I cannot bring back the trophy, I will be less likely to hunt.”