Twitter CEO Jack Dorsey defended the social media giant’s decision to block the New York Post’s reporting about Democratic presidential nominee Joe Biden’s son Hunter and the use of his father’s position to make deals with Ukraine and Chinese businesses.

Dorsey told the Senate Commerce, Science, and Transportation Committee that Twitter initially blocked the story, which centered on three of Hunter Biden’s alleged laptops, because “it was unclear how they were obtained.”

Dorsey said Twitter has “a hack materials policy … around limiting the spread of materials that are hacked.”

The New York Post story was eventually allowed back on Twitter, but the media outlet is still blocked on the platform.

Sen. Ted Cruz, a Texas Republican, said that Twitter and Facebook, which also reduced distribution of the story, “crossed a threshold that is fundamental in our country” by censoring the story and the New York Post.

The owner of a computer repair shop obtained the laptops from Hunter Biden, according to documents he provided. Biden never returned to pick up the devices, and they were turned over to the FBI. Trump ally Rudy Giuliani obtained their contents, reportedly including photos of Hunter Biden taking drugs. The laptops include emails said to detail Biden family business plans that center on using Joe Biden, the former vice president, to leverage deals.

The New York Post story detailed how the laptops were obtained.

“They weren't hiding what they claimed to be the source,” Cruz argued to Dorsey. “Is it your position that Twitter, when you can't tell the source, blocks press stories?”

Dorsey denied it.

“Our team made a fast decision on the enforcement action over blocking URLs, both in tweets and in direct messages,” Dorsey said. “We believe that was incorrect, and we changed it.”

Dorsey said the New York Post can return to Twitter if it takes several steps.

“They have to log into their account, which they can do at this minute, delete the original tweet, which fell under our original enforcement actions, and they can tweet the exact same material to the exact same article, and it would go through,” Dorsey said.