A "Christ-centered" legal group has filed a federal lawsuit against a high school in New York, accusing it of religious discrimination after it disbanded a student Christian club while leaving dozens of other clubs active.

The Arizona-based Alliance Defense Fund claims the Christian club, called Ichthus, was cancelled without notice after being in operation for four years.

ADF filed the lawsuit in U.S. District Court in Islip on behalf of a student at Half Hollow Hills High School East in the Long Island town of Dix Hills.

ADF attorney David Cortman said Ichthus was disbanded even though there was student interest in keeping it going.

"This is pure and simple a case of viewpoint discrimination against Christian students," Cortman told Fox News. "This is a school that has 60 student clubs. They have, of course, a gay-straight alliance; they have a fashion club, which is important because we all have to look good; they have a future lawyers of America, which it is obvious why they didn’t cancel their club.

"They also have a club that deals with the Constitution, which is probably a good club for school officials to take.

"But what is interesting here is that [of] all those clubs, they decide to deny the Christian club."

But Dr. Sheldon Karnilow, the district superintendent, denies that disbanding the club was a discrimination issue. He said the decision was strictly budgetary.

"We don't discriminate in any way, shape or form," he said. "As long as it's a legitimate club with student interest that is not harmful to students, we let a club run."

Karnilow said the school principal is the one who decides which clubs to keep open, based on two criteria: student interest and the availability of a willing faculty adviser. He said the funding for Ichthus was cut "along with about 16 other clubs."

Ichthus was created more than four years ago by a student who graduated last spring. But when the boy's sister entered the school as a freshman in the fall and wanted to attend the club, she was told it had been canceled.

The girl's mother, identified only as "Mrs. P," told Fox News her daughter was devastated and said, "They have all this diversity ... I don't understand why they were picking on us."

Mrs. P. said she went through nearly the same fight with her son to get the club established. She said the club was given the green light only when she threatened to take legal action.

This time, when complained to the school board and was told that the club would not be reinstated, she took immediate legal action.

Karnilow insists the Ichthus Club had only six or seven students attending regularly, and he says no staff adviser was available.

But Cortman says the club had 30 students who attended regularly, with about 55 students on the roster. In addition, he says, the student and her mother offered to find an adviser to lead the group.

Karnilow insists the school district was more than fair. He said it even offered to transport Mrs. P's daughter to the district's other high school, where the Ichthus Club has a more robust attendance.

But Cortman says, "The other 60 clubs do not have to get on a bus, leave their last period early, miss some work, travel to another school, find their own transport home.

"So first of all, it is discrimination no matter how you look at it, even if there is some sort of accommodation. That is no different than arguing it is OK to sit at the back of the bus, because you are going to get to your destination anyways."

Mrs. P. also said that the district's other high school said her daughter was not allowed to attend its Ichthus club.

Karnilow said that if there is sufficient student interest, the district will consider reinstating the club next year.

But the ADF is demanding that the club be reinstated immediately, and it says it will file an injunction in the next couple of weeks if it isn't.

Lauren Green currently serves as Fox News Channel's (FNC) chief religion correspondent based in the New York bureau. She joined FNC in 1996.