Those arrested during the raid of four McDonald's in Scottsdale, Tempe and Mesa were being held on suspicion of identity theft. It will take more time to determine whether any of them are illegal immigrants as officials suspect, said Maricopa County Sheriff Joe Arpaio.
Deputies also searched a mansion in the tony Phoenix suburb of Paradise Valley owned by Richard Coulston, who owns the restaurants, Arpaio said. Coulston was not arrested.
Deputies could be seen on local television stations swarming around Coulston's mansion, and McDonald's workers were shown crying and hugging each other.
It's a shame that Friday's arrests had to happen at the fast-food restaurant, which is "more than just a business," Arpaio said.
"It's an American institution," he said, adding, "a place that my kids and yours could always count on for their first job ever. That these McDonald's restaurants targeted in today's investigation are giving jobs away to people using false IDs or perhaps working here illegally is a shame."
McDonald's Corp. referred comment to Coulston's company, R&L Management.
In a statement, attorney Julie Pace - acting as a company spokeswoman - said people shouldn't jump to conclusions without all the facts.
"The company has trained its managers and hiring personnel regarding proper hiring procedures," said Pace, one of several lawyers representing business groups that have unsuccessfully tried to overturn the state's employer sanctions law. "Any individuals unable to meet the legal requirements for establishing authorization to work are not hired."
Pace said the company was cooperating with the sheriff's office.
Arpaio said deputies were tipped off in November to the McDonald's they raided by a caller to their illegal immigration hot line, and the tipster alleged several employees bragged about being illegal immigrants.
Deputies used government databases to identify 51 workers who appear to be illegal workers, and were looking for the 30 outstanding suspects.
County officials said if any of the workers turns out to be an illegal immigrant, it could be their fourth civil case under the employer sanctions law, which penalizes employers for knowingly hiring illegal immigrants. The law, which is more than two years old, carries license suspensions and revocations for those who knowingly make illegal hires and is designed to reduce the economic incentive for immigrants to cross the border.
Authorities across Arizona have examined several dozen complaints of employer sanctions violations. But no business licenses have been revoked and only three civil cases have been filed - against a Subway sandwich franchise in west Phoenix, a now-defunct northwest Phoenix amusement park and a custom furniture maker in Scottsdale.
Danny's Subway and the amusement park, Waterworld, acknowledged violating the employer sanctions law and settled their cases with the county. The case against the furniture store is ongoing.
By Associated Press Writer Amanda Lee Myers; AP Writer Mark Carlson contributed to this report