UPDATE: Fox issued a statement this afternoon after he was processed and released.
According to Politico, Fox was led out in handcuffs before the hearing began while shouting, "I'm within my First Amendment rights, and I'm being taken out."
Fox's "Gasland" took on oil and gas companies for their policy of using hydraulic fracturing to obtain fuel from underneath layers of otherwise unpenetrable rock. The process has been accused of contaminating drinking water in rural mid-Atlantic towns, and Fox's film is famous for showing residents set fire to the water coming out of their kitchen sinks. He was in the Capitol shooting a follow-up.
A credentialed ABC News news team was also denied entrance, according to the Huffington Post.
Capitol police spokeswoman Sgt. Kimberly Schneider told Indiewire that the arrest took place at about 10:30 am ET. As of 12:45 pm ET, Fox was still under arrest and being processed.
Fox is in the process of shooting a sequel to "Gasland," which was nominated for best documentary at the 2011 Academy Awards.
According to a blog post written by fellow documentarian AJ Schnack, Fox had hoped to release his "Gasland" sequel early this year.
It will include cameos from those at every level in the debate, including U.S. senators, small-town inspection officers, and petition-wielding parking-lot activists. “On the one side is a very powerful industry and their political and media allies,” says Fox. “But there are small groups of extremely dedicated activists fighting fracking in every state where it’s a threat. It’s incredibly inspiring to see these mini-labs in democracy in action.”