The U.S. Department of Justice's Civil Rights Division has opened an investigation into an incident involving a Brooklyn coffee shop and U.S. Rep. Dan Goldman that sparked widespread attention online over the weekend.

The controversy began when the social media account for Poetica Coffee shared a now-deleted post showing a photo of Goldman inside the chain’s 7th Avenue location in Park Slope.

The post read in part: "At Poetica, we don't serve racists, fascists, homophobes, genocide enablers, or anyone in between." The business said it had refunded Goldman's purchase and told him, "Don't ever come back to Poetica."

Goldman responded to the post, saying he had stopped by the coffee shop with his 7-year-old daughter. He said a barista allowed his daughter to use the bathroom and that he purchased a coffee afterward "in return for her kindness."

The incident quickly drew attention online.

The war in Gaza and support for Israel remain major issues in the Democratic primary race for New York's 10th Congressional District.

Goldman and his opponent in Tuesday's primary election, former New York City Comptroller Brad Lander, have taken different positions on issues related to Israel. In this case, Lander sided with Goldman.

"There are plenty of ways to lobby elected officials and express outrage at the votes they've taken without turning coffee shops into places people don't feel welcome," Lander wrote in a statement. "I'm glad Poetica took down their post, and I thought Rep. Goldman's reply was extremely gracious."

The controversy follows a recent vote by members of the Park Slope Food Co-op to boycott products from Israel.

News 12 made multiple attempts to contact the owner of Poetica Coffee for comment but did not receive a response.