A federal judge in Michigan this week ordered the Trump administration to turn over communications from Rudolph W. Giuliani and other advisers on the president’s controversial travel ban. Those suing over the matter hope the documents will bolster their bid to prove the ban was motivated by animus toward Muslims.

Giuliani has been a key figure in the ban even before the first version was signed, and judges across the country have pointed to statements by the former New York mayor and close Trump ally as they have ordered the ban frozen. The judges have noted particularly a comment Giuliani made on Fox News in January, in which he seemed to suggest he helped the president craft a legal way to prevent Muslims from entering the U.S.

“So when first announced it, he said, ‘Muslim ban.’ He called me up. He said, ‘Put a commission together. Show me the right way to do it legally,’ ” Giuliani said at the time.

U.S. District Judge Victoria A. Roberts ordered the government to turn over to those suing a memo that Giuliani crafted, along with all “documents or communications” about the travel ban from him and several other Trump advisers, including Attorney General Jeff Sessions, White House Chief Strategist Stephen K. Bannon and senior adviser Stephen Miller during the period just before the election, before they were in their current roles.

Judges have noted Miller’s comments, too, in putting the latest version of the ban on hold.

“We believe these documents will show exactly how the Muslim ban that Donald Trump called for on the campaign trail turned into the executive order he issued a week after taking office,” said Miriam Aukerman, senior staff attorney at the ACLU of Michigan, in a written statement. “If the administration now still refuses to turn over these papers, the question will be: What is it trying to hide?”

The case in Michigan is not one of the two that have put Trump’s latest travel ban on hold. It is proceeding at a slower pace and it could be significantly impacted by rulings elsewhere. On Monday, a three-judge panel with the U.S. Court of Appeals for the 9th Circuit Court is scheduled to hear arguments in one of those cases. The U.S. Court of Appeals for the 4th Circuit heard arguments this week.

In an interview, Giuliani said he was willing to turn over whatever documents he still had — but he noted the court’s order was directed to the government, not to him personally. “Basically, the advice was you can’t ban, based on any religion,” Giuliani said.

A Justice Department spokeswoman declined to comment.

Giuliani also said his comment on Fox News had been misinterpreted, and that Trump had not asked him how to craft a legal Muslim ban.

“That’s the incorrect interpretation,” Giuliani said. He said Trump more accurately asked, “what can he do legally to keep the country safe” or “How can I do whatever I’m going to do legally?”

“For example, what we told him is he shouldn’t do a Muslim ban,” Giuliani said. “The way I interpreted it, it was, ‘Tell me what I can do legally,’ not, ‘Tell me how I can get around and do a Muslim ban and find some kind of legal justification for it.’ We did just the opposite.”

Roberts ordered the government to turn over Giuliani’s memo by May 19 and the rest of the materials by June 2.