A 14-year-old boy who allegedly threw a chair out of a moving train has been charged by police after his mother saw footage of the act on social media and turned him in.

The video has been watched more than 20,000 times since it was posted on Facebook yesterday and appears to show the young male throwing part of a chair from the train as it travels along an overpass. Cars can be seen driving below, as what looks to be the cushion of a train seat flies out of the carriage.

Another male can be heard yelling "Oh no don't hit a f---ing car, bro" as the chair piece is heaved out of the open door.

"Lol. Oi that's going to be on the news," another says.