Claims have surfaced that a teenager booted from the SCG for a “bloody stupid” act was placed in a police cell after being removed from the stadium.

The brief confrontation unfolded in the final quarter of Port Adelaide’s clash with the Sydney Swans at the SCG on Sunday, when Port Adelaide’s Aliir Aliir took a mark on the goal line and ran toward the boundary fence.

Footage showed a young Swans supporter lift his arm and allegedly hurl an item - later identified as a cardboard clapper, freely given out to spectators - toward the player.

Aliir seemed to shared a few heated words with the teenager before returning to play.

NSW police and SCG staff members confronted the young attendee before removing him from the stadium.

Speaking to 3AW on Monday, a man claiming to be the boy’s grandfather accused police of placing the teenager in a cell after the “bloody stupid” incident.

“My grandson was the one who threw the banner,” he told the radio station.

“I’m really upset. It really is an embarrassment.”

When asked whether the teenager had been removed from the premises, the man claimed he had been placed “in a police cell”.

“He’s in a police cell with police, and they’re discussing (the incident) with him,” he told the station.

“He’s a stupid kid, he doesn’t realise what he’s done.”

NSW Police have not yet confirmed whether the boy was placed in a cell.

The Swans said in a statement on Sunday that the club was working to ascertain whether the young fan was a member.

“A fan was removed from the stadium in the final quarter of Sunday’s match against Port Adelaide at the SCG, after (allegedly) throwing an object at Port Adelaide player Aliir Aliir,” the statement read.

“The club has reached out to Aliir, and we will continue to educate fans that any form of abusive behaviour is not welcome.

“The Sydney Swans would like to reiterate our zero-tolerance stance on all forms of abuse.”