A communication between President Donald Trump and a world leader prompted a whistleblower complaint that is now at the center of a dispute between the director of national intelligence and Congress.

CNN reports:

The concern was first revealed by The Washington Post, which reported that an official in the American intelligence community was so bothered by a “promise” Trump made to a foreign leader that the official filed a formal whistleblower complaint with the inspector general of the intelligence community, citing two former US officials familiar with the matter. CNN has not independently confirmed the detail about a “promise” made to the foreign leader. The source who spoke to CNN would not disclose the foreign leader with whom Trump was alleged to have spoken. The Office of the Director of National Intelligence declined to comment. The White House has not responded to CNN’s request for comment. The details of the complaint are shrouded in mystery, even as the fight between the House Intelligence Committee and acting director of national intelligence has been brought to the fore by committee Chairman Adam Schiff. While not privy to the details of the complaint, the California Democrat wrote in a letter to the Office of the Director of National Intelligence last week that, from what he has gleaned, he believes “the serious misconduct at issue involves the President of the United States and/or other senior White House or Administration officials.”It’s the first time Trump’s direct involvement in the complaint has been reported, according to the Post. The complaint was filed on August 12. White House records show Trump had spoken to or interacted with five foreign leaders in the previous five weeks, the Post reports: Russian President Vladimir Putin, North Korean dictator Kim Jong Un, the Prime Minister of Pakistan, the Prime Minister of the Netherlands and the Emir of Qatar. However, it’s not clear that the communication that inspired the complaint was with any of those leaders.

The Last Word with Lawrence O’Donnell broke down the story last night with guests NSC senior director Ned Price, former Obama deputy national security advisor Ben Rhodes and NY Times columnist Nicholas Kristof.

Watch: