Jose Magalhaes took his two young boys and his elderly father to watch a big Portuguese soccer game, thinking it would be a treat for all. Instead, he and his family are at the center of a national scandal over alleged police brutality.

Live video of a police officer beating Magalhaes with a truncheon in front of his sons outside the stadium Sunday, and also punching his 66-year-old father, has sparked outrage in Portugal and led to an official investigation by authorities of alleged abuse of power by police.

Magalhaes told The Associated Press on Tuesday that police had allowed him and his sons to leave the stadium before others because his children, aged nine and 13, were being crushed as fans inside celebrated a result that gave Benfica, the club his family supports, the Portuguese championship title.

"It was supposed to be a day of celebration," Magalhaes told the AP at his lawyer's office Tuesday in his hometown of Matosinhos, about 300 kilometers (180 miles) north of the capital Lisbon.

Police declined to comment to the AP, but the national headquarters said in a statement it has opened an investigation into the incident. The government department that oversees the police is also analyzing police conduct.

Dramatic video footage, played widely on Portuguese television and on social media, shows the Magalhaes family by a low wall outside the stadium, where the youngest child sat and drank a bottle of water. There were few other people in the vicinity because police were holding rival fans inside the stadium at Guimaraes, also in northern Portugal, to avoid clashes in surrounding streets.

An officer questioned Magalhaes, then punched his father before using a truncheon to beat Magalhaes on the ground while his 9-year-old screamed "Dad! Dad!"

"The policeman came over ... and asked us why we had brought children to a stadium if we knew there might be trouble," Magalhaes said. "I told him, gesticulating, that he should be more concerned about the problems inside the stadium."

"The next thing I know he's on top of me," said Magalhaes, a slim, 42-year-old businessman in the real estate sector.

Another policeman in riot gear with a shield kept the 9-year-old child away and tried to pick him up as he cried.

Magalhaes said his first worry was his youngest son.

"The kid didn't understand what was going on. I wanted to get over to him and comfort him ... and calm him down," he said. Instead, Magalhaes was handcuffed and taken away.

Magalhaes said the policeman alleged at an initial court hearing on Monday that Magalhaes spat at him, a claim Magalhaes denied. Magalhaes said the police had previously been kind to him and his family by allowing them to leave the stadium early.

The incident has brought a flurry of investigations and charges.

Magalhaes' lawyer, Sonia Carneiro, says police have brought a complaint of threatening behavior and obstruction against Magalhaes. After an initial hearing Monday, the public prosecutor's office is now investigating whether there is enough evidence to proceed with a formal charge against Magalhaes. There is no deadline for a decision.

Magalhaes says he and his father intend to file a complaint against the police, though he acknowledges that the one officer who hit him does not represent the entire police force.

Meanwhile, he has to explain what happened to his children. He and his wife had taught them that the police are their friends, he said, and they "couldn't understand why the police acted like they did."

As he nurses his bruises and stiffness, Magalhaes hopes an invitation from Benfica to watch next weekend's final game of the season will help banish the bad memory.

"The physical part will heal faster than the psychological part," he said.