Last month, the Trump administration said it could not comply with a court order to disclose the names of people who met with the president at Mar-a-Lago in part because they do “not maintain any system for keeping track” of them.

In response to a lawsuit filed by the nonprofit Citizens for Responsibility and Ethics in Washington, or CREW, seeking to make the records public, Department of Justice lawyers insisted “the Secret Service does not maintain any ‘visitor logs’ at Mar-a-Lago.”

But seven Mar-a-Lago members and their guests told ProPublica that uniformed officers, who appear to be Secret Service, stand at the doors of the resort on weekends when the president is there, and hold lists of people approved for access.

Anne Weisman, CREW’s attorney on the case, said the visitor lists, whether they are compiled by Trump Organization employees or the federal government, are subject to the Freedom of Information Act and should be made public.

Several Mar-a-Lago members and guests said security checked their names against lists if they entered the club on weekends when Trump was present. When Lynn Aronberg, who runs a public relations firm in West Palm Beach, visited the resort this year during one of the president’s visits, she had to provide her driver’s license to officers at the door. While she is not certain the officers were Secret Service agents, Aronberg said they were dressed very differently from the police officers she is used to seeing around Palm Beach. The officers held a clipboard, and checked her name against what looked to her like a list of names attached to it.

Other visitors remember officers holding a clipboard at the door. Boca Raton resident Heidi Klein has visited Mar-a-Lago “probably 10 times” as a member’s guest or for charity events. She also said the officers looked at a list before allowing her through, and that they always check guests’ names.

Phil Nicozisis, a Mar-a-Lago member who runs his own real estate development company, says that every time he brings a guest to the Palm Beach club, he has to email the club and provide the visitor’s full name. (This was true before Trump’s inauguration but Mar-a-Lago is now stricter about the rule.)

Members are told of the president’s visits in advance, Nicozisis said, so that they can prepare for the heightened security and scrutiny of those entering.

The Secret Service and Department of Justice declined to comment on the Mar-a-Lago visitor lists, citing the ongoing lawsuit with CREW. The Trump Organization did not respond to ProPublica requests for comment.

Former Secret Service officials and other experts say it's exceedingly unlikely that the government does not know who is getting close to the president. In addition to keeping track of people coming into the club, the Secret Service also regularly conducts criminal background checks on any guests or staff members who will spend more than a passing moment in physical proximity to the president. This protocol applies at Mar-a-Lago in the same way it does everywhere else the president goes.

“It makes zero sense to me that they would have no records related to [protective intelligence] name checks or background checks at Mar-a-Lago,” said Jonathan Wackrow, who served on the Secret Service’s presidential protection detail for 14 years. “You would never want to be surprised.”

Watchdog groups and journalists have tried to find out who has had audiences with Trump at the place he’s dubbed the “Winter White House.” Advocates contend the public has a right to know who has access to the president, especially since it can be bought for $200,000 a year, the current price of a Mar-a-Lago membership. This money flows into the Trump Organization, enriching the president.

Kathleen Clark, a law professor at Washington University Law School who writes and teaches about government ethics, says the list of presidential visitors at Mar-a-Lago would give the public necessary information.

“The president is enriching himself, probably at the expense of the country, because he’s inducing people to pay him and his companies so they can have access,” Clark said.

Trump has spent 25 days of his presidency at Mar-a-Lago. The Secret Service recently told the court that the division responsible for conducting background checks did not have any records related to presidential visitors between Trump’s inauguration and March 8. During that span, Trump visited Mar-a-Lago three times and was spotted at a 500-person cancer fundraiser sitting next to former Canadian Prime Minister Brian Mulroney and Boston financier and club member Howard Kessler, along with their spouses.

Trump has known Kessler for years and Mulroney is a former head of state. It’s unclear if they avoided a background check by the Secret Service or if their background checks simply went undisclosed in the administration’s legal response.

In response to the CREW lawsuit, the government only disclosed the names of 22 people they considered to be presidential visitors. All 22 were government, diplomatic or support staff who went to Mar-a-Lago as part of Japanese Prime Minister Shinzo Abe’s delegation in February.

The federal judge in the case, Katherine Failla, also expressed “surprise” at the minimal visitor records handed over, but declined CREW’s motion to sanction the government.

During President Obama’s two terms, the White House released its visitor lists, with some national security exemptions, as part of a settlement of lawsuits seeking the records. Media pool reports would sometimes fill the gaps, namely on presidential trips to Camp David; flights aboard Air Force One; and vacations to Martha’s Vineyard.

Previous administrations, including those of Presidents Bill Clinton and George W. Bush, refused to voluntarily disclose presidential visitor lists altogether. Over eight years, Bush spent roughly 490 days at his ranch in Crawford, Texas, which he called the “Western White House,” and guests included former Israeli Prime Minister Ariel Sharon, former Chinese President Jiang Zemin and German Chancellor Angela Merkel. Such visits were typically made public through the media pool reports.

But the differences between previous presidential vacation spots and Trump’s are stark. “Mar-a-Lago is a commercial establishment,” Clark said. “There was no indication that President Bush was charging any of the people who visited his ranch. It was not a commercial relationship, and he was not enriching himself, so there was not the same kind of public interest in knowing who was paying for access.”