Screenshot by CNET

Instagram said a hate-filled manifesto linked to the El Paso massacre suspect wasn't first uploaded to the Facebook-owned site as suggested by the owner of the extremist site 8chan where the document was discovered.

A spokeswoman for Facebook said that on Saturday the company disabled an Instagram account tied to the suspected gunman in the El Paso, Texas, attack earlier that day that killed 22 people and wounded another two dozen. The Instagram account hadn't been active for more than a year, she said.

Instagram is working with law enforcement, she said Tuesday. She directed any additional questions to the FBI. The FBI declined to comment.

That statement comes after Jim Watkins, owner of the 8chan message board, suggested in a YouTube video that the document had been loaded to his site by a different user. Watkins, who appeared in front of an image of Benjamin Franklin, said the site had made law enforcement "aware" of the manifesto after it appeared.

He also suggested -- though didn't directly state -- that the man accused of the Walmart attack in El Paso had posted the manifesto on Instagram.

"First of all, the El Paso shooter posted on Instagram, not 8chan," Watkins said in the video. "Later, someone uploaded a manifesto. However, that manifesto was not uploaded by the Walmart shooter. I don't know if he wrote it or not, but it was not uploaded by the murderer. That is clear."

Watkins offered no evidence to support his statement.

Law enforcement officials told The Wall Street Journal Friday that the alleged shooter did post his manifesto on 8chan prior to the shooting. The hate-filled document was posted at 10:15 a.m. on Aug. 3, 25 minutes before the shooting began. A law enforcement official told the Journal there was no indication that 8chan users alerted the authorities.

Now playing: Watch this: What might happen to 8chan? (The Daily Charge, 8/7/2019)

8chan, an anonymous forum, is a magnet for trolls who delight in racist, sexist, violent and crass posts. Watkins' video was titled "Sorry for the inconvenience, common sense will prevail," an apparent reference to the title of the 2,300-word manifesto, which was called "The Inconvenient Truth."

The Twitter account of the House Committee on Homeland Security posted Tuesday a request for Watkins to appear in front of Congress. Rep. Bennie Thompson, a Democrat from Missouri and chairman of the committee, and Rep. Mike Rogers, a Republican from Michigan, penned the letter and referenced the El Paso mass shooting as "at least the third act of white supremacist extremist violence" linked to the site.

"Experts have described 8chan as a platform for amplifying extremist views, leading to the radicalization of its users," the representatives said in the letter. "Americans deserve to know what, if anything, you, as the owner and operator, are doing to address the proliferation of extremist content on 8chan."

🚨BREAKING🚨: Homeland Security Chairman Thompson & Ranking Member Rogers sent a letter to 8chan owner Jim Watkins demanding he come before Congress and answer questions on the site’s extremist content.



cc: @infinitechan pic.twitter.com/8SDSI1rFLj — House Homeland Security Committee (@HomelandDems) August 6, 2019

8chan's official Twitter account posted an image of an email sent by Watkins to the House committee Tuesday in response to the letter. The tweet says the Watkins' email was "identified as spam." In his email, Watkins said he is returning to America -- he currently lives in the Philippines -- and would be available to speak over the phone.

"Rest assured I am not an extremist," he said in the email.

“This message was identified as spam.” Just making sure you received it, @HomelandDems. pic.twitter.com/8K3JNpHPzp — 8chan (8ch.net) (@infinitechan) August 7, 2019

The Philippine National Police's Anti-Cybercrime Division began monitoring 8chan on Tuesday, according to a report from CNN Philippines. Watkins and his adult son, who is also a site administrator, reside in the Philippines. Chief Police General Oscar Albayalde said it might shut down the site depending on what division discovers.

Since the discovery of the manifesto, 8chan has lost technical support from services such as security platform Cloudflare. 8chan went offline early Monday. At the time, a tweet from the site's official account said it'd be down for 24 to 48 hours. 8chan isn't currently available.

Fredrick Brennan, 8chan's founder, who's no longer associated with the site, told The New York Times on Sunday that the site needs to be shut down. "It's not doing the world any good," he told The Times. "It's a complete negative to everybody except the users that are there. And you know what? It's a negative to them, too. They just don't realize it."

Earlier this year, the gunman who attacked two New Zealand mosques and the gunman who attacked a California synagogue posted their manifestos to 8chan.

Watkins and administrators for 8chan didn't immediately respond to a request for comment.

Originally published, Aug. 6, 6:59 a.m. PT.

Updates, 7:10 a.m.: Adds FBI's response; 11:43 a.m.: Includes Facebook's response; 3:28 p.m.: Adds letter from Homeland Security committee. Aug 7: Adds Watkins response to Congress. Aug 8: Adds Philippine police details. Aug 9: Adds details from law enforcement officials reported by the Journal.