A phone interview between national AM radio host Mo Kelly and infamous Donald Trump ally Roger Stone got extremely contentious after Stone was heard referring to Kelly as a "negro."

During a dial-in interview Saturday morning on KFI, Stone commented on his recent grant of clemency from President Donald Trump. Stone was convicted on seven felony counts over his involvement in Russian interference of the 2016 presidential election, and Trump used his pardon power to release him last week.

After Kelly took issue with Stone's fast-track pardon, the Trump advisor claimed his conviction was unfair because he faced a jury of "political opponents." Kelly pushed back on his self-victimization by pointing out, "There are thousands of people treated unfairly daily. Hell, your number just happened to come up in the lottery," he said. He then added, "I'm guessing it was more than just luck, Roger, right?"

After a long pause, Stone can be heard mumbling, presumably to someone else on his end of the line, "I don't really feel like arguing with this negro."

A seething exchange followed, with Kelly demanding for Stone to repeat what he just called him under his breath, and Stone denying that he used the racial slur.

Listen to the full audio, below:

Kelly later tweeted about the exchange: