THE schoolboy who's become an internet sensation after turning the tables on a bully has told how he snapped after years of cruel taunts about his weight.

Sixteen-year-old Casey Heynes says he has been bullied nearly every day at his school, Chifley College, at St Marys, but could take no more when Year 7 student Ritchard Gale tormented and attacked him last Monday.

"All I was doing was defending myself. I've never had so much support," he said during an interview with A Current Affair.

Casey reveals he'd been targeted by a new group of Year 7 boys who had started picking on him and teasing him about two weeks prior to the fight.

The Year 10 student said he found himself surrounded by the students when he went to get a school timetable before class.

As Ritchard backed him against the wall and started throwing punches, Casey said he felt scared and worried that others in the group would also start hitting him.

Eventually, he snapped, picking Ritchard up over his shoulder and throwing him to the ground.

The brawl was recorded on the mobile phone of another student who later posted the video online where he has earned "hero" status.

Asked if he was a superhero, he laughed and said: "No I wish I was."

The video, which was taken off YouTube on Tuesday, has gone viral worldwide spawning dozens of websites and facebook pages congratulating Casey for fighting back.

It also sparked a media storm with St Marys residents claiming television stations were offering up to $1000 for information about the fight.

Channel Nine won the race to sign up Casey after rival Today Tonight on Seven interviewed Ritchard's mother who said her son should apologise.

Yesterday, Ritchard was unrepentant. Asked whether he was sorry for attacking Casey, he bluntly replied: "No."

The issue has divided the western Sydney community.

"Good on him. I was so happy to see a bully finally getting what he deserved," one St Marys resident said.

"I don't condone violence but when kids stage an attack like that and record it to humiliate the victim it's wrong."

But another resident Jayne Saunders said: "He could have broken that little kid's neck."