The Britain's Got Talent judge got eggs thrown at him while watching an act of two singing brothers perform during Saturday night's live finale broadcast of the reality talent competition's seventh season, Reuters reported.
A 30-year-old viola player named Natalie Holt reportedly ran towards Cowell from backstage and threw a few eggs at him only to be escorted out by security staff. Following the attack, Cowell took his jacket off and resumed judging.
Holt, with her string ensemble called Raven Quartet, had reportedly appeared on Britain's Got Talent last season but didn't make it very far.
"I basically took a stand against people miming on television and against Simon and his dreadful influence on the music industry," the musician told the Telegraph website, according to Reuters.
Despite the interruption and inconvenience the incident caused, no charges are apparently being filed against Holt.
"As a result of her misguided actions, the police were called. However, we have decided to take no further action at this stage," a show representative told Reuters.
Holt reportedly apologized to the brothers duo for disrupting their performance in a statement released by the show's organizers.