Rep. Elijah Cummings, the top Democrat on the House Oversight and Government Reform Committee, is demanding information from the Secret Service about its role in vetting the Russians who attended a June 2016 meeting at Trump Tower with Trump family members and campaign representatives.

"According to press reports, the meeting took place on the 25th floor of Trump Tower, one floor below that of then-candidate Trump who was also reportedly at Trump Tower at that time and had a Secret Service protective detail," Cummings, D-Md., wrote in the letter to Secret Service Director Randolph Alles. "It remains unclear what security protocols the Secret Service may have had in place at Trump Tower while the protectee was present."

During an interview with ABC News on Sunday, Jay Sekulow, a member of President Trump's outside legal team, questioned why Secret Service allowed Russian lawyer Natalia Veselnitskaya and Russian-American lobbyist Rinat Akhmetshin into Trump Tower to meet with Donald Trump Jr., then-campaign chairman Paul Manafort and Jared Kushner.

The three men met with Veselnitskaya, after Trump Jr. was told she had damaging information on Hillary Clinton. A translator was also in attendance.

"Well, I wonder why the Secret Service, if this was nefarious, why the Secret Service allowed these people in," Sekulow said. "The president had Secret Service protection at that point, and that raised a question with me."

The Secret Service responded to Sekulow's statements Sunday and said it would not have screened or vetted anyone Trump Jr. was meeting with in June 2016 because the president's son wasn't under Secret Service protection.

Cummings now wants information from the agency about how it vetted people at Trump Tower, including an explanation of what screening or vetting occurred for those attending meetings on June 9, 2016, the date of Trump Jr.'s meeting with Veselnitskaya.

The Maryland Democrat also requested documents and communications related to the vetting of individuals who attended meetings at Trump Tower that day, and documents and communications related to the screening of Veselnitskaya, Akhmetshin, and Rob Goldstone, a British publicist who orchestrated the meeting.