A judge is hearing arguments about whether Roger Stone, a longtime friend of President Donald Trump, violated a gag order in a case that grew out of special counsel Robert Mueller's Russia probe.

Prosecutors have argued that Stone's social media posts violate an order banning him from publicly commenting on his case. U.S. District Judge Amy Berman Jackson imposed the order in February after Stone posted a photo of the judge with what appeared to be crosshairs of a gun .

Since then, Stone has made additional Facebook and Instagram posts, including one that asks "Who Framed Roger Stone?"

Roger Stone, a longtime confidant of President Donald Trump, accompanied by his wife Nydia Stone, left, arrives at federal court in Washington, Tuesday, July 16, 2019. (AP PhotoSait Serkan Gurbuz)

Roger Stone, a longtime confidant of President Donald Trump, accompanied by his wife Nydia Stone, left, arrives at federal court in Washington, Tuesday, July 16, 2019. (AP PhotoSait Serkan Gurbuz)

Stone is charged with witness tampering and lying to Congress during Mueller's investigation into ties between the rump campaign and Russia.

Defense lawyers deny that he violated the judge's order.