House Democrats are coming up with ways to keep the identity of the whistleblower in their impeachment inquiry a secret from their GOP colleagues, fearing that President Donald Trump’s congressional allies will expose him or her.

Rep. Raja Krishnamoorthi (D-IL) on Monday confirmed CNN and the Washington Post reports on Monday revealing that Democrats involved in the inquiry are considering measures as extreme as having the whistleblower testify remotely in front of Congress’ two intelligence committees using voice and appearance-altering technology.

Democrats have also contemplated keeping the whistleblower hidden behind a partition if he or she testifies in person, according to the Post.

Krishnamoorthi, who sits on the House Intelligence Committee, told CNN host Wolf Blitzer that such steps are necessary to protect the whistleblower from Trump, who has been attacking him or her for weeks.

“He wants to know the identity of the whistleblower,” Krishnamoorthi said. “And so this extremely unusual situation, unfortunately, demands extreme measures in terms of protecting the security of the whistleblower.”

“We cannot allow the President to somehow get to the whistleblower or threaten him or discourage him or her from telling their side of the story and us learning what exactly is the extent of the alleged scheme displayed in his complaint,” he continued.

Blitzer asked the congressman if he trusts Republicans in Congress to protect the whistleblower’s identity.

“I’d like to trust the secrecy of our identities of whistleblowers and other important facts to all members of our committee,” Krishnamoorthi replied. “However, the fact of the matter is that we can’t guarantee 100% assurance or safety for this whistleblower in the current situation using normal methods or measures. And so that’s why we have to resort to these extreme measures which you described.”

Watch Krishnamoorthi below: