Arizona officials involved with a Republican-commissioned recount of the November presidential election in the state’s largest county on Thursday brushed off concerns raised by the Justice Department this week, raising the possibility of a clash between state and federal authorities over the audit.

Pamela S. Karlan, who heads the Justice Department’s civil rights division, wrote a letter to the president of the Arizona state Senate on Wednesday suggesting that the recount of nearly 2.1 million ballots in Maricopa County by a private contractor may not comply with federal law, which requires that ballots be securely maintained for 22 months following a federal election.

“We have a concern that Maricopa County election records, which are required by federal law to be retained and preserved, are no longer under the ultimate control of elections officials, are not being adequately safeguarded by contractors, and are at risk of damage or loss,” she wrote.

In her letter, Karlan also asked questions about a plan by the private contractor hired to lead the audit, Florida-based Cyber Ninjas, to interview voters and ask them whether they cast ballots in November, as county records show. Karlan said such interviews could violate federal laws prohibiting voter intimidation.

Former Arizona secretary of state Ken Bennett, the audit’s spokesman, said in an interview Thursday that state Senate President Karen Fann plans to tell the Justice Department in her own letter that there is no need for federal involvement.

Fann plans to argue that the ballots at the Arizona Veterans Memorial Coliseum in Phoenix are being guarded 24 hours a day and are not in any danger, he said.

Bennett added that Cyber Ninjas has not yet begun interviewing voters but said the company has pledged to do nothing that would constitute intimidation.

“This is a matter between the Arizona Senate and Maricopa County,” he said. “We don’t see any grounds for anyone else to intervene.”

The Justice Department weighed in for the first time as Arizona’s top elections official, Democratic Secretary of State Katie Hobbs, separately outlined a series of problems observed by election experts representing her office who have monitored the recount, including ballots that were left unattended.

Hobbs later told reporters that she was among a bipartisan group of secretaries of state who met with Justice Department officials on Thursday to voice concerns about what is happening in Arizona.

“This is potentially precedent-setting,” she said. “We think they’re writing the playbook here to take this across the country.”

In an interview with The Washington Post, Hobbs said that she is not sure what actions the Justice Department will take. “I think that they’re at a place where they don't think they legally can send in observers,” she said. “But they're certainly paying attention to what's going on.”

A spokesman for Fann did not respond to a request for comment. The recount’s official Twitter account, @ArizonaAudit, late Wednesday tweeted, “Arizona has the authority to conduct this audit without interference from the Feds!”

On Thursday morning, it announced simply: “The audit continues!”

A Justice Department spokeswoman did not respond to a request for comment.

Chris Sautter, a political strategist who teaches election law at American University, said that if federal officials believed ballots were in danger of not being preserved, they could file a lawsuit in federal court and ask a judge to stop the audit or order changes. He noted that federal law carries criminal penalties for elections officials who do not comply.

The law cited by the Justice Department in its letter dates to the civil rights era, when it was passed to prevent local elections officials from destroying records that showed that Black voters had been thwarted when they attempted to register to vote, Sautter said.

Some Republicans in the state reacted angrily to the inquiry from the Biden administration.

GOP State Sen. Wendy Rogers, who took office in January, tweeted a warning that the Justice Department should stay out of the situation. “Do not touch Arizona ballots or machines unless you want to spend time in an Arizona prison,” she wrote.

The GOP-led state Senate ordered the recount over the objections of the Republican-controlled Maricopa County Board of Supervisors, using a subpoena to remove equipment and ballots from county facilities.

In her letter Wednesday, Hobbs raised concerns about the security of the process, which began last month and has proceeded slowly.

Three experts acting on behalf of her office who have spent time on the Coliseum floor in recent days told reporters Thursday that they have seen activities that depart from best practices followed by election officials.

They said procedures differed from counting table to counting table. Stacks of ballots were not being recounted as they were moved and handled, as would otherwise be standard to ensure none are lost or misplaced.

Ryan Macias, former acting director of certification and testing for the U.S. Election Assistance Commission, said he watched as a team of ballot counters separated a stack of ballots from others and placed it on a nearby table, where they sat for a time unattended and unmonitored.

After he flagged the issue, the ballots were “migrated” back into a box with other ballots.

“There is no way that if you had to go back and identify which ballots they were [that you could], because they did not stay in their original order,” he said.

Hobbs also noted in her letter that the state Senate has a lease to use the Coliseum for the recount only until May 14, when local schools have booked the building to conduct high school graduation ceremonies.

Bennett said that, so far, about 200,000 votes have been counted — less than 10 percent of the total. He said audit officials are exploring ways to box up material needed for the recount and then return to the Coliseum later to finish the process. He said he has been told the building is not currently booked again until early July.

He said Hobbs’s complaints were “totally unfounded” and “simply reexpressions of her opposition to the audit from the very beginning.”

The contentious recount comes months after President Biden’s narrow victory in Arizona was certified by the Maricopa County Board of Supervisors and Gov. Doug Ducey (R), who has praised the state’s election.

State and federal judges rejected allegations the vote was marred by fraud. And two audits ordered by the county concluded in February that election machinery had worked properly and counted votes accurately.

But former president Donald Trump and his supporters have continued to allege without evidence that there were problems with the vote. The chief executive of Cyber Ninjas, Doug Logan, has echoed those claims, and Trump allies are raising private funds to supplement $150,000 in taxpayer money that Fann agreed to spend on the audit.

Trump has said that he believes the Arizona audit will lead to other states initiating similar reviews — a distressing prospect to elections officials who have said partisan-led post-election audits will continue to erode the public’s trust in democratic elections.

Among Trump’s allies, expressing enthusiastic support for the Arizona effort is becoming a new way to show allegiance to his claims about the 2020 election.

On Thursday, Rep. Elise Stefanik (R-N.Y.) backed the Arizona audit during an appearance on former Trump adviser Stephen K. Bannon’s podcast. Her comments came as she is challenging Rep. Liz Cheney (R-Wyo.) for a leadership post in the House Republican conference over Cheney’s vocal condemnation of Trump’s election falsehoods.

“I fully support the audit in Arizona,” Stefanik said. “We want transparency and answers for the American people. What are the Democrats so afraid of?”

Marianna Sotomayor and Dan Zak in Phoenix contributed to this report.