Intro:

Portuguese prosecutors investigate conduct of police who beat a Benfica fan in front of his children.

Script:

Police approached Jose Magalhaes outside the Guimaraes stadium where Benfica had just won the Portuguese league title on Sunday.

Magalhaes said police had allowed him and his two sons, who were wearing Benfica jerseys, to leave the stadium before other fans because the children were being crushed.

Footage shows an officer questioning Magalhaes, then punching his elderly father, twice, before using a truncheon to beat Magalhaes, who was on the ground, while his 9-year-old child screams.

Members of the general public seemed completely shocked by the incident, and when a few tried to calm the situation down, they appear to have to threatened themselves.

The district prosecutor said in a statement that it has opened an investigation into alleged abuse of power.