(CNN) The Des Moines Register reporter who exposed a man's racist tweets from 2012 is no longer with the publication after readers revealed his own controversial social media posts.

"We took appropriate action because there is nothing more important in journalism than having readers' trust," Executive Editor Carol Hunter said in an opinion piece, responding to local outrage to the original story. It is unclear if the reporter quit or was fired.

Aaron Calvin, a reporter for the Register, worked on a profile on Carson King, a 24-year-old man who raised more than $1 million for an Iowa children's hospital after a request for beer money during a televised college football program.

And on Tuesday, after Calvin discovered racist tweets King posted seven years ago, readers surfaced tweets on Calvin's social media that included derogatory language against black people, gay people, same-sex marriage and women, The Washington Post reported.

"We're revising our policies and practices, including those that did not uncover our own reporter's past inappropriate social media postings," wrote Hunter. "That reporter is no longer with the Register."

Once the posts were shared widely, Calvin tweeted, "I have deleted previous tweets that have been inappropriate or insensitive. I apologize for not holding myself to the same high standards as the Register holds others," according to a screengrab published by the Washington Post.

The apology post is also no longer available online.

"I did apologize for my tweets and I regret them and wouldn't publish them now," Calvin told CNN on Friday.

Calvin, 27, told CNN he was 18 and in high school when he posted the tweets.

"I would have never said the word out loud at that point in my life, as I never had," he said, referring to a racial slur.

In an interview with BuzzFeed News on Friday, Calvin said he felt "abandoned" by the newspaper because he followed standard editorial practice by conducting a social media search on the person he was writing about.

"This event basically set my entire life on fire," he said.

Readers ask why the paper looked into King

While doing the profile, Calvin asked King about the comments, which included posts comparing black mothers to gorillas and another joking about black people who were killed in the Holocaust.

While editors and the Register discussed whether to include them in the profile, King held a news conference to apologize, calling the postings "an attempt at humor that was offensive and hurtful."

"Obviously I've made mistakes in my past; everyone has," he said in the conference, CNN affiliate WHO reported . "And I really hope people see at this point in my life, I'm grown, I'm caring, I'm generous. I hope that's what people focus on."

After, King came forward and admitted the old tweets, the paper decided to include the information at the bottom of the story for transparency, Hunter said.

Readers quickly questioned why the Register had dug so far into King's life, surfacing posts from when he was 16 in 2012.

Hunter addressed the criticism, saying that numerous fundraising scams have been recently exposed.

"As journalists, we have the obligation to look into matters completely, to aid the public in understanding the people we write about and in some cases to whom money is donated," she said.

Anheuser-Busch pulls support

The money King raised came after he held up a sign reading "Busch Light Supply Needs Replenished" with his Venmo username on ESPN's "College GameDay" program earlier this month.

Money poured in, and after buying one case he decided to donate the rest to the University of Iowa Stead Family Children's Hospital.

Anheuser-Busch and Venmo promised to match whatever he raised. Busch Beer also promised to send him a year's supply of beer cans with his name and face on them.

Anheuser-Busch spokesperson Matt Kohan told CNN on Wednesday that the company would still donate more than $350,000 to the hospital as promised, but it had rescinded its beer offer. Instead, it will add the value of the year's supply to its donation.

"Carson King had multiple social media posts that do not align with our values as a brand or as a company and we will have no further association with him," the company said in a statement to CNN.

Money keeps coming in

The controversy hasn't stalled donations, though. King told reporters Tuesday that he still planned to raise $2 million for the hospital.

"I'm just glad that Busch and Venmo are matching the donations and that we can continue to make a difference for the hospital," King told CNN by phone on Wednesday evening.

"We're actually at $1.5 million in donations. I'm happy that we can keep helping them, the kids and families of the hospitals," he said.

Venmo did not respond to a CNN request for comment. Reached Wednesday evening, the University of Iowa Stead Family Children's Hospital said it would not be issuing a statement at this time, though last week, University of Iowa Healthcare spokesman Tom Moore told CNN the hospital was coordinating a time for King to "bring the donation over and present the check" in early October.

On Wednesday, Iowa Gov. Kim Reynolds recognized King for all the money he's raised, signing a proclamation declaring Saturday as Carson King Day.

When asked for comment, Reynolds spokesman directed CNN to a tweet the governor shared Wednesday.

"You can make a mistake in your life, and still go on to do amazing things," she tweeted. "@CarsongKing2, thank you for reminding us all of that! #IowaProud."

This article has been updated to add comments from Calvin to CNN regarding his tweets.