House Homeland Security Committee Chairman Bennie Thompson (D-Miss.) is questioning whether the newly selected head of Border Patrol participated in a controversial Facebook group filled with racist and sexist posts from border agents.

In a letter on Monday, Thompson asked U.S. Customs and Border Patrol (CBP) to reveal whether the agency took action against Rodney Scott over his engagement with a Facebook group for agents that ProPublica first reported contained lewd and xenophobic posts.

Scott was officially tapped to lead CBP last week, replacing Border Patrol chief Carla Provost, who retired amid heavy criticism over her participation in the secret Facebook group, which had about 9,500 members.

"On Friday, I received notification that Mr. Rodney S. Scott has been selected as the new Chief of the U.S. Border Patrol," Thompson wrote in the letter to the acting commissioner of CBP.

"According to media reports, Mr. Scott engaged with at least one social media site - the Facebook group 'I'm 10-15' - in which CBP personnel communicated vulgar and discriminatory comments," Thompson wrote. "I would like to understand the extent to which Customs and Border Protection (CBP) reviewed and assessed Mr. Scott's engagement with social media sites in which personnel from CBP engaged in racist and hateful dialogue ... prior to his selection to lead the U.S. Border Patrol."

ProPublica revealed the Facebook group's activities in July. Since then, CBP has fired three Border Patrol agents over their involvement in the group, though an internal review recommended the agency fire seven people and take disciplinary action against 20.

Thompson is asking CBP to procure documents around any investigation into Scott, who was reportedly a member of the group, and any disciplinary action he faced as a result.

Scott, a 27-year veteran of Border Patrol, was one of several agency leaders who participated in "I'm 10-15," a reference to the code for "aliens in custody." Its status was previously set to "secret."

One post uncovered last year featured an illustration of Rep. Alexandria Ocasio-Cortez (D-N.Y.) engaged in oral sex with a detained migrant, while another showed President Trump forcing Ocasio-Cortez toward his crotch with the comment, "That's right bitches. The masses have spoken and today democracy won."

In response to a post about a 16-year-old Guatemalan migrant who died in May at a Border Patrol station, one member wrote, "If he dies, he dies," while another posted an Elmo GIF that read, "Oh well."

Provost, Scott's predecessor, slammed the Facebook group as "completely inappropriate" after ProPublica's report last year. But several lawmakers called for her to resign after it was discovered that Provost actively participated in the group for months after she was appointed to the head of the agency.

Though Provost herself was not linked to any offensive material, the revelation emphasized the ties between the highest ranks of CBP and the controversial group, which sparked condemnations and questions from top lawmakers.

CBP did not immediately respond to The Hill's request for comment.