A Tucson high school student and his family were deported after the teen was found with marijuana at school and police called the U.S. Border Patrol after learning he and his family were illegal immigrants.

The incident raised concern among immigrants rights activists, but Tucson police said the officer acted appropriately by calling immigration agents.

Police were called to Catalina High Magnet School Thursday after school officials found a small amount of marijuana in the backpack of a ninth-grader who appeared to be under the influence, said Chyrl Hill Lander, a spokeswoman for the Tucson Unified School District.

Police then asked the boy's parents to come to the school, and once they arrived an officer asked to see their driver's licenses. The parents told officers they had been living illegally in the U.S. for six years, along with the ninth-grader and their 17- and 12-year-old sons, assistant police chief Roberto Villasenor said Monday.

The officer called the Border Patrol and agents were sent to the school, said Richard DeWitt, Tucson Sector spokesman. They took the boy and his parents into custody, then went to a middle school and picked up the 12-year-old.

The mother and two boys were taken to the Mexican border in a procedure called voluntary return. The father was held for formal deportation because he had been apprehended various times by the agency, DeWitt said. Their names were not released.

Police officials said the officer handled the case correctly. The boy had committed a crime, and department policy allows officers to call the Border Patrol when they suspect someone is here illegally, Villasenor said.

"We can't lose track of the fact that an administrator came across a juvenile who was violating the law, in possession of marijuana," Villasenor said. "That is a crime in this country, whether you are here illegally or not."

An immigrants rights proponent said allowing immigration agents into schools could create more mistrust and fear in the immigrant community.

"Now you have people who are afraid to call the police when they have been robbed because they are afraid the police will come and instead of investigating the crime will ask them about their immigration status," said Jennifer Allen, director of Tucson-based Border Action Network.

Lander said she was unaware of other immigration-related arrests at Tucson schools, and said the district would have preferred that police called the Border Patrol once they left campus.

A Tucson police policy lets officers who have already stopped a person on suspicion of committing a crime to ask immigration agents to respond to determine if the person is in the country legally.

Villasenor said the Police Department doesn't want crime victims or witnesses who are here illegally to fear coming forward because they might be deported, and doesn't want its officers to become immigration agents. But they will call federal agents when they believe they are required.

"While we don't want to put a chilling effect on anyone calling us, we are also obligated to do our job," Villasenor said.