Special counsel Robert Mueller has reportedly interviewed several digital experts who were part of the President Trump campaign as his team investigates ties between the Trump campaign, the Republican National Committee, and the data analytics firm at the center of the Facebook controversy rocking the technology world, Cambridge Analytica.

Over the past week, reports have come out how Cambridge Analytica allegedly obtained data, improperly, from tens of millions of Facebook users. The data firm was hired to work for the Trump campaign in the summer of 2016 by then-digital advisor Brad Parscale.

The digital experts interviewed by Mueller's team primarily worked for the RNC and as a result, interacted frequently with the campaign and Cambridge Analytica, sources told ABC News.

This isn’t the first time it was reported Mueller showing interest in the data firm.

Mueller's team, who is investigating Russian interference in the 2016 election and if the Trump campaign colluded with the Kremlin, last year reportedly requested the firm provide emails from any of its employees who worked for the Trump campaign. Cambridge Analytica adhered to the request.

Former White House chief strategist Steve Bannon oversaw the data firm’s program to obtain Facebook data with the intention of developing voter profiles, former Cambridge Analytica employee Christopher Wylie told the Washington Post in a report on Tuesday.

The effort led by Bannon tested phrases including “drain the swamp” and “deep state” as a form of voter persuasion, Wylie said.

Bannon had previously worked for Cambridge Analytica as their vice president and secretary until he moved over to working for the Trump campaign in 2016.

Facebook announced on Friday that Cambridge Analytica, its parent company Strategic Communication Laboratories, Wylie, and others would be suspended from Facebook in response to the reports that not all data that had been obtained had been properly deleted.

Cambridge Analytica has denied that it did anything improper with the Facebook data.