The House Committee on Homeland Security issued a subpoena Wednesday to the owner of the fringe internet message board 8chan, a move that comes as its role in hosting extremist content is drawing international scrutiny.

Jim Watkins, who acquired the website in 2016, has been ordered to appear before the committee on Sept. 5 at 9:30 a.m. ET.

8chan, which has been connected to numerous mass shootings in recent months, has struggled to stay online in recent days since one of its major service providers, Cloudflare, ceased doing business with it.

Investigators are “reasonably confident” that the suspect in the El Paso, Texas, shooting, Patrick Crusius, 21, posted an anti-immigrant screed on the website prior to the attack. The screed referred to the mass killing in Christchurch, New Zealand, in which a white supremacist is accused of gunning down 51 people at two mosques and posting links to a livestream of the attack on 8chan.

Last week, the Homeland Security committee informally requested that Watkins appear “to provide testimony regarding 8chan’s efforts to investigate and mitigate the proliferation of extremist content, including white supremacist extremist content, on your website.”

The subpoena Wednesday is the first the committee has issued this year.

Watkins, an American who has lived in the Philippines for years, has been in touch with the committee, according to Adam Comis, spokesman for the committee’s chair, Rep. Bennie G. Thompson, D-Miss.

“We believe a subpoena was the best course of action to receive testimony in a timely manner and because his primary residence is outside the U.S.,” Comis said in an email.

Eight days ago, Jim Watkins wrote on Twitter in a response to the committee that he was “on his way back to America as we speak.”

Watkins’ son, Ron Watkins, who is the current administrator for 8chan, did not immediately respond to a request for comment.