WASHINGTON — Congressional opponents of the communist regime in Cuba are condemning a New York City schoolteacher who took a group of teenage students to the island nation in an apparent violation of federal travel restrictions.

“It’s totally inappropriate to teach schoolchildren to circumvent federal law,” a congresswoman who represents a district in South Florida with a large Cuban-American population, Rep. Debbie Wasserman Schultz, a Democrat, said yesterday. “It’s more than inappropriate. It’s irresponsible.”

City officials are investigating how a history teacher at the Beacon School on the Upper West Side of Manhattan, Nathan Turner, was able to take a group of students on a nine-day trip to Havana earlier this month. Both the Department of Education and the school principal have said they did not approve the trip. Federal law limits educational trips to Cuba to college and graduate students who are traveling for a minimum of 10 weeks. Violators can receive up to a $65,000 fine.

The Treasury Department’s Office of Foreign Assets Control, which enforces American sanctions, would investigate violations, but an agency spokeswoman, Molly Millerwise, yesterday would not confirm or deny that a federal inquiry was under way. A spokesman for the city’s education department, David Cantor, said to his knowledge, the federal government had not contacted city officials.

“We don’t know that there were any federal violations,” he said. Mr. Cantor said city investigators would refer the case to prosecutors if they deem it appropriate, but he added that it is possible no action will be taken.

Beacon’s principal, Ruth Lacey, did not return messages yesterday.

A Cuban-born congresswoman and the ranking Republican on the House Foreign Affairs Committee, Rep. Ileana Ros-Lehtinen, said, “It seemed as if the school trip was planned only to score political points and not for primarily educational purposes.”

Mayor Bloomberg has also criticized the trip, which secured approval from at least two elected officials, Rep. Jerrold Nadler, and the lieutenant governor, David Paterson.

Washington-based foes of Fidel Castro were even stronger in their rebukes yesterday, saying the teacher should be subject to prosecution and fines if violations are found.

“Whether a teacher agrees or doesn’t agree with a policy, that’s his or her issue, but dragging students to do something that is questionable or illegal is really beyond the pale,” the executive director of the Center for a Free Cuba, Frank Calzon, said.

A director of the U.S. Cuba Democracy Political Action Committee, Mauricio Claver-Carone, said the travel restrictions exist for a reason: to give America leverage to push Cuba to address its long history of human-rights violations and political oppression. “The law is there for a very important reason,” he said. With regards to the teacher, he said, “He should definitely be fined.”

The trip was organized by Pastors for Peace, an affiliate of the Interreligious Foundation for Community Organization, which has long opposed American economic sanctions on Cuba. The group’s executive director, the Reverend Lucius Walker Jr., did not return a call yesterday.