Former Housing and Urban Development Secretary (HUD) Julian Castro defended his brother's controversial decision to publish the names of some President Trump donors, arguing it was important for people to know about businesses in San Antonio that donated to the president.

"I believe that people need to know what businesses in that city that are profiting off of the backs of Hispanic customers are turning around and putting that money back into the pockets of a politician, in Donald Trump, that is actively making the lives of Hispanics in this country worse," Castro said while appearing at the Iowa State Fair on Friday.

His comments came amid a media frenzy over that decision by his twin brother Joaquin. While some like White House adviser Kellyanne Conway derided the apparent attempt to intimidate Trump donors, others, like her husband, pushed back on the criticism.

Castro, like George Conway, pointed out that the donor information was already available, tweeting: "That is public information, that kind of information is put out all the time... he did not put down anybody's private information -- he did not put down their addresses, he did not put down their phone numbers."

JOAQUIN CASTRO FACING BACKLASH FROM ALL SIDES FOR POSTING TRUMP DONOR INFORMATION

On Friday, Castro added of his brother's actions: "What he did is not doxxing. Anybody who understands what doxxing is knows that he did not do that."

In his initial tweet, Rep. Castro accused donors of "fueling a campaign of hate" with their contributions. Fox News reported that those donors people who also contributed to the Texas representative himself. A local business owner, Wayne Harwell, said he would no longer support Castro after the congressman's stunt on social media.

Another individual on the list, William Greehey, also gave thousands of dollars to Castro during his first two campaigns, the Washington Free Beacon reported.

Meanwhile, a local oil business owner and executive, Justin Herricks, whose name was also on Castro’s list, called the tactic “ridiculous.”

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“I think some of the Democratic rhetoric is more hateful than some of Trump’s rhetoric,” he said. “I think the San Antonio community needs to take a real deep look at what Castro is doing. Why is he doing this?”

Fox News' Brooke Singman contributed to this report.