A security guard has been suspended from his job at a Cardiff shopping centre after video of him grabbing a boy by the throat was posted online.
The incident shows the guard at an entrance to St David's 2 in the city centre telling the boy and his friends to "get out or I'll chuck you out".
He then takes the boy by the arm to clear him from the doorway before grabbing hold of his throat.
St David's said it was "not the level of conduct expected from our officers".
Jason Mann's son was one of the group present.
He told BBC News Online the teenagers were in the city centre on Sunday skateboarding before deciding to go into St David's to get some food.
"They went inside to a cafe and were about to order when two security guards approached them and they were asked to leave, because they had skateboards with them and the management didn't want them there.
"Stupidly perhaps, they tried to enter through another door. That's when they were confronted.
"I appreciate what security guards do and what they're confronted with sometimes but grabbing a 15-year-old boy by the throat is totally unacceptable," he said.
Mr Mann, from St Mellons, Cardiff, said he felt the boys had been labelled by the fact they were carrying skateboards and by their clothing.
"They are a really good group of boys and well-behaved. They are being very dismissive of the incident as if it's nothing, but the parents involved don't feel the same.
"After being grabbed around the throat, I'm not sure I'd be so dismissive. [My son] is more concerned about the guy losing his job.
"I'm a firefighter so I come across anti-social behaviour on a regular basis, being spat at, rocks thrown by youths, and I'd never react in that way."
He said the incident had been logged with the police.
St David's' centre manager Mark Nott said: "We have been made aware of this incident and the security officer involved has been suspended with immediate effect.
"This is not the level of conduct we expect from our officers and we apologise to all parties involved. A full investigation in now taking place and we are liaising with the customers concerned directly."