Northern Ireland's police ombudsman is investigating the conduct of an off-duty police officer who appeared to restrain a teenage boy after a snowball was thrown at the man's vehicle.
A video of the incident, which happened in Limavady, County Londonderry, on 27 February, has been shared more than 100,000 times online.
It shows the officer confronting the 14-year-old in a shop in the town.
The police watchdog said it was investigating the incident.
Ciarán Shiels, of Madden & Finucane Solicitors, acting on behalf of the family, said the 14-year-old was taken to Altnagelvin Hospital and "treated for physical injuries" after his school contacted his parents.
"The school authorities themselves initiated a complaint to the PSNI after he presented for class," he said.
The solicitor said additional footage of the incident had since emerged and he understood this would also be made available to the ombudsman.
A formal meeting is to take place with the ombudsman on Wednesday, he added.
The footage shows a struggle and an exchange of words between the boy and the off-duty officer.
The officer can be heard trying to explain what he is doing and asking the boy if he understands.
Near the end of the video the boy is moved into what appears to be a store room and the door is then closed.
'Disturbed and angry'
A police ombudsman spokesman said: "We are investigating an altercation involving a police officer and a schoolboy.
"Our investigators have begun the process of gathering evidence to assess the appropriateness of the officer's actions during the incident."
The Police Service of Northern Ireland (PSNI) said it had received a report that a teenager was assaulted at about 10:20 GMT on 27 February.
"It was reported that snowballs had been thrown in the area and that one had struck a passing vehicle," added the PSNI.
The boy's parents told BBC Radio Foyle they were "disturbed and angry" and have asked for the footage to be removed from social media.
"It's very sad that he was treated so poorly," they said.
"This officer should have noticed very quickly that he was in serious distress."