ABC television said on Monday it had received about 1,500 complaints about the sexually-charged performance by American Idol runner-up Adam Lambert at the American Music Awards on Sunday.

Millions of viewers saw Lambert simulate oral sex with a back-up dancer, plant a passionate kiss on the mouth of a male keyboard player and gesture to the audience with his middle finger during the closing act of the live music awards show.

Lambert, 27, said his goal was not to piss people off, it was to promote freedom of expression and artistic freedom.

ABC cut the most controversial part of his act -- Lambert rubbing the face of a male dancer in his crotch -- from the U.S. West Coast telecast that aired later on Sunday.

But by then, the singer's racy rendition of his debut single For Your Entertainment was already on its way to becoming one of the most provocative TV moments in the music industry since Madonna and Britney Spears kissed on the MTV Video Music Awards show in 2003.

Adam Lambert was among the top 10 most popular topics on Twitter on Monday.

American Music Awards producers, Dick Clark Productions, said they were unaware from rehearsals what Lambert had planned. We did not expect the impromptu moments, a spokeswoman told Reuters.

An estimated 14.2 million viewers watched the American Music Awards telecast, the largest audience since 2002, ABC said, based on preliminary viewing figures.

Lambert, 27, who publicly declared he was gay after American Idol ended in May, said his act with dancers in bondage costumes, was no different from the erotic performances of some female pop singers. He added that much of the sexual energy he brought to Sunday's show was in the moment.

Adrenaline is a crazy, crazy, crazy feeling. Some of the things I love most about performing is when you're up there and all of the sudden you just have these feelings, this rush that comes over you, Lambert told CNN afterward.

The Federal Communications Commission (FCC), which has strict rules on the broadcast of indecent or profane material, said it could not confirm or deny receiving complaints.

The FCC fined CBS $550,000 for broadcasting a fleeting glimpse of Janet Jackson's breast to roughly 90 million TV viewers of the 2004 Super Bowl half-time show, which Jackson famously blamed on a wardrobe malfunction.

It was unclear whether ABC could be at risk of an FCC fine because Lambert's performance was broadcast around 11 pm in most of the nation, outside the FCC's 6am-10pm time frame prohibiting the broadcast of indecent material.

Entertainment Weekly music reporter Michael Slezak wrote that Lambert's first major TV outing since the American Idol show felt less like a genuine expression of his high-octane sexuality...and more like a carefully planned stab at dominating the post-AMA blogosphere/water-cooler discussion.

Lambert released his debut album, also titled For Your Entertainment, on Monday and by midday it was No. 11 on the iTunes albums charts.