Dan Scavino Jr., the Trump administration's social media director, violated a federal law that restricts public officials from using their positions to engage in certain political activity, according to a letter from the US Office of Special Counsel (OSC).
Scavino violated the law, called the Hatch Act, with a tweet in April calling for President Donald Trump's supporters to defeat GOP congressman Justin Amash in a primary.
In the Tweet, Scavino called Amash "a big liability" and asked the #TrumpTrain to "defeat him in primary."
The White House did not immediately respond to a request for comment.
The episode is just another example of how important tweets and other social media missives have become in politics. Trump, of course, is a prolific Twitter user, and his tweets make national news on an almost daily basis.
The OSC said it has issued Scavino a warning.
"Mr. Scavino has been advised that if in the future he engages in prohibited political activity while employed in a position covered by the Hatch Act, we will consider such activity to be a willful and knowing violation of the law," the OSC letter reads.