New York (CNN) Stephen Miller, the controversial senior White House policy adviser who holds hardline views on immigration , promoted stories from white nationalist and fringe media organizations to staffers of the far-right website Breitbart, a trove of leaked 2015 emails published Tuesday revealed.

The emails were published by the Southern Poverty Law Center , a non-profit organization that monitors hate groups. Miller sent the emails before he had ascended to the White House, but while he was working as a senior aide for then-Sen. Jeff Sessions.

One of the emails, published by the SPLC and later obtained by CNN, showed Miller sent a Breitbart staffer a link to VDARE, a prominent white nationalist website.

In another email, Miller sent a Breitbart employee a link to the fringe right-wing media organization InfoWars.

Miller did not respond to CNN's request for comment.

White House press secretary Stephanie Grisham told CNN that she had "not seen the report" from the SPLC. But she attacked the group as a "far-left smear organization."

"They libel, slander, and defame conservatives for a living," Grisham said in an email. "They are beneath public discussion."

Hours after she provided that statement, Grisham told CNN by email she had still not reviewed the emails which showed Miller promoting content from extremist websites. Grisham did not immediately reply when asked if she or anyone at the White House planned to look at the SPLC report on Tuesday.

Heidi Beirich, director of the SPLC Intelligence Project, said in response, "The emails that were provided to the Southern Poverty Law Center stand on their own. We based our reporting on the content of the emails and backed up our analysis with our own research and evidence."

The SPLC said the emails from Miller were leaked by Katie McHugh, a former Breitbart employee who was fired in 2015 after anti-Muslim remarks following a terrorist attack in London.

In the years since her time at Breitbart, McHugh has renounced her views and worked to expose members of the far-right.

Tuesday's cache of emails were the first in what the SPLC said would be a series.

In a July 21, 2015, email Miller sent McHugh a story published by InfoWars, the fringe media organization notorious for peddling conspiracy theories.

InfoWars and its founder, Alex Jones, have been sued by Sandy Hook families for promoting the false conspiracy theory that the school shooting was staged. In a sworn deposition taken earlier this year, Jones conceded the shooting was real, claiming a "form of psychosis" caused him at the time to believe it was staged.

The InfoWars story Miller sent McHugh was about right-wing evangelical leader Rev. Franklin Graham warning that the United States was "under attack by Muslims at home and abroad."

In a separate October 23, 2015, email, published as part of Tuesday's SPLC report, McHugh asked Miller about "the chances" Hurricane Patricia could drive "mass migration to the U.S. border" because of damage it would do to Mexico.

Miller replied, "100 percent." He then said the survivors could be given temporary protected status, and that it needed to be "the weekend's BIG story."

McHugh wrote back, "Wow. Ok. Is there precedent for this?"

Miller answered with a link to a VDARE story which documented other instances when refugees were offered temporary protected status.

In his current position at the White House, Miller has some influence over whether the United States provides temporary protected status to refugees. The Trump administration denied providing that status to Bahamians affected by Hurricane Dorian in September.

McHugh, who was not available for comment Tuesday, told the SPLC that Miller also suggested over the phone in 2015 that she aggregate a story from American Renaissance, another white nationalist online publication.

"Miller asked me if I had seen the recent 'AmRen' article about crime statistics and race," McHugh told the SPLC. "I responded in the affirmative because I had read it. Many of us [on the far right] had read it. I remember being struck by the way he called it 'AmRen,' the nickname."

Neither a spokesperson for Breitbart nor Alex Marlow, the website's editor-in-chief, responded on Tuesday to CNN's requests for comment.

But Elizabeth Moore, a Breitbart spokesperson, did tell the SPLC, "The SPLC claims to have three- to four-year-old emails, many previously reported on, involving an individual whom we fired years ago for a multitude of reasons, and you now have an even better idea why we fired her. Having said that, it is not exactly a newsflash that political staffers pitch stories to journalists -- sometimes those pitches are successful, sometimes not."