The CIA analyst who sparked the impeachment investigation is being protected by armed security officers.

The analyst, whose identity has not been confirmed, continues to work on issues relating to Russia and Ukraine and is driven to and from work by the armed officers when threats against him increase, the Washington Post reported. The threats tend to increase when President Trump tweets about the whistleblower.

The whistleblower submitted a complaint about Trump’s interactions with the leader of Ukraine, including concerns about Trump urging Ukrainian President Volodymyr Zelensky to investigate his political rival Joe Biden in a July 25 phone call.

Some Republican lawmakers have alleged that CIA analyst Eric Ciaramella filed the complaint and have demanded that he testify in Trump’s impeachment proceedings.

Ciaramella, 33, was Ukraine director on the National Security Council at the end of the Obama administration and was briefly the acting senior director for European and Russian affairs in the early months of the Trump administration. He is now a deputy national intelligence officer for Russia and Eurasia on the National Intelligence Council.

Lawyers for the whistleblower, who have not confirmed or denied whether they are representing Ciaramella, said any attempt to out their client would be the "pinnacle of irresponsibility."