U.N. Ambassador Nikki Haley has been accused of a violating a law limiting government employees' political activity by voicing support for a South Carolina congressional candidate.

In a letter sent Tuesday to the U.S. Office of Special Counsel, Citizens for Responsibility and Ethics in Washington, or CREW, accused the former South Carolina governor of violating the Hatch Act when she retweeted one of President Donald Trump's Twitter messages earlier this month supporting Republican Ralph Norman.

On June 19, the day before Norman faced off with Democrat Archie Parnell in South Carolina's 5th District, Trump sent several tweets praising the millionaire real estate developer as someone who would be a help to him in Congress and urging voters to "#VoteRalphNorman tomorrow!"

Later that day, according to CREW, Haley retweeted the first message from her verified Twitter account, which lists her as U.S. ambassador to the United Nations. At the time, the group said, Haley had at least 356,000 followers.

Haley deleted the message after journalists questioned it on Twitter. The group said Haley should still be investigated and disciplined. A Haley spokeswoman didn't immediately respond to a text message.

Haley wouldn't be the first Trump administration official accused of sending tweets in violation of the Hatch Act, a 1939 law allowing government officials to personally donate money to political committees or engage in a variety of partisan activities, so long as they do so during their personal time and don't use government resources.

Earlier this month, White House social media director Dan Scavino was issued a warning for using an official-looking Twitter account to call for a Michigan congressman's defeat. CREW filed a complaint in that case also, and Scavino was warned if he engages in such activity in the future, the office will consider it a "willful and knowing violation of the law."

Other Cabinet officials campaigned in a special election to fill Georgia's 6th District seat, with Health and Human Services Secretary Tom Price and Agriculture Secretary Sonny Perdue stumping for Republican Karen Handel earlier this month. An invite for that event reportedly didn't mention the title "secretary" instead calling the two Cabinet officials "special guests."

Earlier this year, Haley made a nominal donation of $100 to the GOP primary campaign of Norman, a former state lawmaker who was one of her chief legislative supporters when she served as governor.