Google is weeding out the hate after coming under fire for allowing a neo-Nazi site to appear as a top result when someone searches for whether the Holocaust happened.

As of Monday, users reported that they no longer saw a white supremacist site appear at the very top of the results, mixed in with sites for Jewish museums and ones that show the Holocaust was real.

"Understanding which pages on the web best answer a query is a challenging problem and we don't always get it right," said a Google spokesperson, who did not explicitly mention the controversy.

Google has recently "made improvements" to its algorithm that will instead surface "more high-quality, credible content on the web," the spokesperson told NBC News, noting that the search algorithm will continue to be tweaked over time.

This latest change occurred after a report that the Breman Museum, a Jewish heritage museum in Atlanta, was relying on an advertising grant from Google to pay to have its site appear higher in Holocaust denial search results in order to combat the presence of a white supremacist site. The cost of the grant amounted to up to $2 per click to divert users to the museum's site, a museum official told The Guardian.

It's not the first time Google has altered its search algorithm, which uses different factors to determine which pages rank higher in the results — a trusted enough method to propel the site to become the biggest and most influential search engine in the world.

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In 2010, Google said it changed its algorithm after a New York Times report found that an online eyeglass business was taking advantage of bad reviews that garnered it a high ranking, in turn giving it more business. Google at the time was hush-hush about how it changed its algorithm, saying it wanted to continue to make it hard for "bad actors" to find a loophole.

Google's technology was changed again after people spoke out about how typing in "are Jews evil" in the autocorrect function resulted in offensive terms. Also, when people searched "who runs Hollywood?" the result, "Jews," was scrubbed last year. Google said its algorithm incorrectly gave "authority" to a site that suggested so because it was linked to over and over again.

The Google search page. NICHOLAS KAMM / AFP - Getty Images file

But Heidi Beirich, intelligence project director for the Southern Poverty Law Center, said Tuesday that Google has a long way to go to "clean up its act." While searching for "did the Holocaust happen?" no longer shows one white supremacist site at the top, searching for "is the Holocaust real?" still provides a site up high that claims it's a hoax.

Beirich said the center met with Google earlier this year after they were alarmed to find a site about Martin Luther King Jr. was actually a front for white supremacist ideology.

"Facebook is getting slaughtered on the fake news front, but in many ways, this Google problem is more insidious," Beirich told NBC News. "People might assume that what they're getting is vetted, and that certainly is not the case."

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She suggested that Google not deal with these issues as one-off controversies but, instead, put together a task force that looks at the systemic problem of hate speech online.

"You can go down a rabbit hole of hate because they're going to keep providing it to you," Beirich said.

Jessie Daniels, a sociology professor at Hunter College in New York specializing on racism online, said search engine companies are not under any obligation to give people unfettered results that uphold false and racist beliefs.

She added that the spread of birtherism, which falsely claimed President Barack Obama was not born in the United States, was allowed to thrive online because of the propping up of certain search results.

"Google doesn't have to make the secret sauce of its algorithm public to make changes," Daniels said. "They can certainly say if your site promulgates hatred against an entire group of people ... we're not going to serve it up to users."