With only two grades left to be announced to find out which samba school would win São Paulo's Carnival parade competition, a man jumped security gates protecting the official results and winners' trophies, tearing up the only papers holding evidence of who would take the ultimate prize, Globo is reporting live.

The man appeared to be a reveller of Império de Casa Verde samba school which, according to the results that had already been read, was not going to take one of the top spots in the competition. He has now been arrested and will be held without bail, according to Globo's report.

Once the man jumped the gates, many others followed suit, knocking over tables, trophies and other revellers in their way, and throwing the gates to the side.

Brazilian Military Police moved quickly to stop the mob, but it continued onto Marginal Tietê highway outside the Anhembi Sambódromo.

According to local media reports, the fighting is continuing and property is being destroyed inside and outside the Sambódromo. Many are trying to rip away metal walls surrounding the floats the samba schools used in Friday and Saturday's parades. Someone set fire to the floats, which destroyed Pérola Negra samba school's work, as orange flames and black smoke billowed above them, according to Brazilian news site Band. The fire is now under control.

A half hour after the mob started, Edilson Casal, Pérola Negra's president, told Band, "They burnt mine, now I'll burn the others." No other fires were set.

According to the Liga das Escolas de Samba, the school that was in the lead before the disruption, Mocidade Alegre, has been named champion, reported Brazilian news site G1. Pérola Negra and Camisa Verde e Branco filled out the last two slots, meaning they will drop down to the lower category of parades called Access for next year's Carnival.