On Friday, Trump’s bearded digital data guru Brad Parscale accepted an invitation to testify before the House Intelligence Committee’s Russia investigation.

The committee is probing whether the Trump camp colluded with Russia in unleashing fake news and propaganda to undermine the candidacy of Trump’s rival, Hillary Clinton. Parscale says he is unaware of any Russian involvement in Trump’s digital and data campaign.

GettyImages-623401428 Brad Parscale, digital director for the Trump campaign, arrives at Trump Tower, November 15, 2016 in New York City. On Friday he agreed to appear before the House Intelligence Committee. Drew Angerer/Getty Images

Parscale is credited with persuading Trump to take digital seriously, and increase spending on the online campaign when it lagged far behind that of the Clinton effort. Unlike other key Trump officials, he has so far stayed out of the spotlight.

A Kansas native, Parscale coordinated Trump’s digital strategy from the San Antonio headquarters of his web marketing firm, Giles-Parscale.

According to a 2016 Wired profile, he started out with a $500 investment after graduating from Trinity University, cold calling potential clients before graduating to building websites for organizations including the Trump Winery and Eric Trump Foundation.

He told the magazine Trump gave “a farm boy from Kansas” a chance. “When I was successful, he continued to reward me over and over again, because I worked hard and produced success,” he said.

During the presidential campaign, the Trump camp paid a whopping $91 million to the firm, which prior to 2016 had no experience in political campaigning.

According to CNN, the campaign’s data operation helped it to figure out where Trump’s message was resonating in states such Michigan and Wisconsin, which were traditionally pro-Democrat but switched to the Republicans and handed Trump victory. 

The campaign was sophisticated and carried on in a vast scale, running as many as 50,000 Facebook ads a day to establish which ones resonated best with voters, reported Wired, and paying for “dark posts” that are publically invisible and show up in a voter’s news feed.

He now works with the pro-Trump America First Policies non-profit group, which was created by Trump supporters to promote the administration’s policies.

Parscale rejects claims that Trump’s digital campaign, which was overseen by the president’s son-in-law Jared Kushner, colluded with Russia, providing them with voter data to target U.S. citizens with fake news and propaganda.

“The only collaboration I am aware of in the Trump digital campaign was with staff provided to the campaign by Facebook, Google and Twitter,” he said in Friday’s statement. “Those experts in digital marketing worked side-by-side with our teams from Giles-Parscale, the Republican National Committee, and Cambridge Analytica to run a professional and winning campaign.”

Kushner is himself a subject of interest to the FBI, which is probing meetings he held in December with a Russian banking CEO and Russia’s ambassador to the U.S. in which he allegedly sought to establish a secret back channel to the Kremlin.

The investigation into the Trump campaign’s digital operation is one part of several complex, fast-moving investigations into alleged collusion with Russia during the 2016 presidential campaign.

Last week Trump’s son, Donald Trump Jr., released emails that showed he had met with a Russian government-linked lawyer offering dirt on Hillary Clinton.