A recount of the 2020 presidential election in Arizona’s largest county is becoming “dangerous,” the Republican chairman of the county board of supervisors declared in a fiery statement late Thursday, a sign of escalating tensions over the controversial election review commissioned by the GOP-led state Senate.

In a statement issued after a lengthy closed-door meeting of the Maricopa County board, whose five members include four Republicans, Chairman Jack Sellers blasted allegations made this week by a private contractor hired to reexamine the election that the audit has already identified problems with the vote.

Sellers said those claims, described in a letter by state Senate President Karen Fann (R), were “false and ill-informed.”

“I know you have all grown weary of the lies and half-truths six months after the 2020 General Election,” he wrote. He added that the private contractors — led by a Florida firm called Cyber Ninjas, whose founder has promoted baseless claims of widespread fraud in the 2020 election — “are in way over their heads.”

“This is not funny,” he wrote. “This is dangerous.”

A spokesman for Fann did not immediately respond to a request for a response, nor did former Arizona secretary of state Ken Bennett, who is acting as a spokesman for the audit.

State Sen. Warren Petersen (R), chairman of the Senate’s judiciary committee, tweeted, “No real answers yet from the County, just angry deflections to President Fanns list of questions. I thought she asked nicely.”

The widening division among Arizona Republicans comes as the GOP nationally has been convulsed by former president Donald Trump’s ongoing falsehoods that the election was rigged.

Republicans in Congress this week ousted Rep. Liz Cheney (R-Wyo.) from a conference leadership position over her insistence on calling out the danger of Trump’s falsehoods. Cheney has made clear that she plans to continue to press the case that indulging false claims about the election could lead to more violence like that seen on Jan. 6 at the U.S. Capitol, when a pro-Trump mob disrupted the counting of the electoral votes by Congress.

In Arizona, where President Biden was the first Democrat to win the state in nearly 25 years, the state Republican Party has strongly backed Trump’s claims, as have several members of Congress. But Republican Gov. Doug Ducey and Maricopa County officials have certified Biden’s win and said the election was fair and secure.

Republicans in the state Senate nevertheless ordered a new review of the results in Maricopa, where Biden won by more than two percentage points, even though state and federal judges had previously dismissed allegations of fraud in Arizona’s vote as lacking evidence.

Fann has insisted that the goal of the review is not to re-litigate the election, but instead to spot problems in election administration that could be corrected for the future. However, Trump and his supporters have made clear that they believe the Arizona audit is the first step to reexamining Biden’s victory across the country.

Last month, the Senate used a legislative subpoena to seize Maricopa’s 2.1 million ballots as well as the county’s voting machines, and turned them over to Cyber Ninjas, whose chief executive, Doug Logan, posted now-deleted tweets endorsing theories that the November vote was marred by fraud.

Logan also has ties to Sidney Powell and Lin Wood, two Trump-allied lawyers who filed unsuccessful lawsuits after the election challenging the results in multiple states.

Since April 23, Cyber Ninjas and its subcontractors have been conducting a hand recount of the ballots inside the Arizona Veterans Memorial Coliseum in Phoenix, examining the paper on which the ballots were printed and performing forensic analysis of the voting machines that they have not fully explained.

Democrats and elections officials nationwide have expressed sharp concern over what they have said are sloppy and shifting procedures being used by the private companies.

Arizona Secretary of State Katie Hobbs (D), who sued and won the right to send observers to watch the process, has been documenting possible security problems, including ballots left unattended on a counting table and laptop computers left open and unlocked.

And the Justice Department last week wrote a letter raising concerns about whether the review might be violating a federal law that requires that election records be preserved for 22 months after Election Day. Fann responded, defending the audit’s security procedures — but also indicating that plans to also interview voters, which the Justice Department had said could be perceived as intimidation, had been put on hold indefinitely.

Meanwhile, Trump’s supporters have been expressing increasing excitement about what the audit might find and are raising millions in private funds to support the effort.

On Wednesday, Fann wrote a letter to the Maricopa County Board of Supervisors asking members to attend a meeting with the state Senate on Tuesday to answer questions about “serious problems” that she said Cyber Ninjas had found at the start of its review.

Fann’s letter alleged that county officials had deleted files from a server and also complained that the county has not turned over forensic images of routers used for the election.

Maricopa County Sheriff Paul Penzone (D) has said that the routers, which are used for all county business, would give the Senate and its contractors access to sensitive law enforcement information and that it would be “mind-numbingly reckless and irresponsible” for the county to turn them over.

In her letter, Fann said that the contractors had also found instances in which the number of ballots in batches provided by the county did not match the numbers noted on a document that accompanied them.

Trump quickly issued a statement Thursday calling Fann’s letter “devastating” and claiming it documented “voting irregularities, and probably fraud,” in the county.

In his statement, Sellers said it is “not true” that files were deleted. He announced that the board will hold its own public meeting Monday to “refute lies and lay out facts about these issues.”

On Friday, the county used its official Twitter account to blast the Senate’s review, repeatedly using the hashtag “#RealAuditorsDont” in a long thread. Entries included “#RealAuditorsDont Release false ‘conclusions’ without understanding what they are looking at” and “#RealAuditorsDont Hire known conspiracy theorists.” Citing the county’s own previously concluded audits, they wrote, “We know auditing. The Senate Cyber Ninja audit is not a real audit.”

The dueling meetings next week could deepen tensions in a state that has already seen numerous angry public protests over the election.

In response to Republican complaints about the election, county officials ordered two forensic audits of the county’s election machines, hiring federally certified firms to conduct the review. Those both ended in February and found the machines provided an accurate ballot count.

The flare-up this week comes as Cyber Ninjas is otherwise being forced to pause its recount efforts because the state Senate rented the Coliseum only through Friday. Next week, the state-owned facility will be used by local high schools for graduation ceremonies.

Cyber Ninjas spent Friday moving boxes full of ballots to off-site storage. The company plans to return to the Coliseum on May 23.

Ken Bennett, the audit spokesman, had originally expressed confidence that the recount would be completed by the end of this week.

Instead, he told reporters Thursday that the contractors had completed their count of only about 500,000 ballots, about a quarter of the total. He has said they will be able to finish reviewing the remaining ballots by June 30, when they must again vacate the Coliseum.