Oktoberfest revellers in nasty fight that really hurts to watch. Caution Graphic Content. Courtesy Live Leak.

A WOMAN was reportedly taken into custody after biting off a young Australian man's lip at Oktoberfest.

Festival-goers filmed the horrific incident, which allegedly occurred in a beer hall at the booze-filled festival in Germany in September.

The Liveleak footage Oktoberfest 2013 crazy girl fights and bites! shows the 23-year-old man, wearing green lederhosen, provoking the woman - who is said to be Alaskan and was sitting at a table in the beer hall - by pushing her and trying to shove something into her mouth.

The person who published the video on YouTube yesterday said they were enjoying their first stein of Oktoberfest when they saw some shoving and started taping.

"Then it went south CRAZY girl, lived up to the stereotypical 'drunk American starting troubl. Bites the poor fellas lip! (sic)" the caption says.

"She did bite it off and spit it on the ground, was arrested ..."

The woman, believed to be aged 30, wearing a yellow dress and devil horn headband, then stood up and starting throwing punches at the man.

The pair tumbled and a male voice was heard calling the woman an expletive before she latched onto his lip and clenched it between her teeth for an agonising 15 seconds before the footage ends.

People could be heard yelling expletives and telling her to let go before the video cut out.

The incident was originally reported in the German newspaper Sueddeutsche Zeitung.

"A 30-year-old woman from Alaska bit the lower lip off a 23-year-old Australian Friday afternoon in the Hofbrautent ... The Alaskan refused to take a breathalyser and a blood sample was accordingly drawn. She is in police custody for criminal assault," the September 30 report said.

The man underwent emergency surgery to have his lip reattached, according to the newspaper.