A top election security official who was fired by President Donald Trump weeks after the 2020 election has confirmed to CNN that he was interviewed in recent months by the special counsel investigating Trump's efforts to overturn the election.

Chris Krebs confirmed to CNN publicly for the first time Tuesday that he has spoken with investigators. Krebs sat down with special counsel Jack Smith's team in early May. The New York Times previously reported that according to a source Krebs had been among those interviewed by Smith's office.

Confirmation that Krebs spoke with Smith's team comes as CNN has learned that the special counsel has also asked witnesses about Trump's knowledge of election security, including a February 2020 Oval Office meeting where the former president praised improvements to the security of US elections, according to multiple people familiar with the matter, before attacking those systems months later.

Smith's team has been inquiring about Krebs' firing and the timeline surrounding it for months. As the director of the Cybersecurity and Infrastructure Security Agency, Krebs rejected Trump's claims of widespread fraud and said there "is no evidence that any voting system deleted or lost votes, changed votes, or was in any way compromised."

That statement soon led to his firing.

"The recent statement by Chris Krebs on the security of the 2020 Election was highly inaccurate, in that there were massive improprieties and fraud," Trump wrote online at the time, as he repeated other baseless conspiracy theories about the election.