Two men who identified themselves as being from the Maricopa County Sheriff’s Office in Phoenix arrived at the state Department of Health on Monday, requesting verification of President Barack Obama’s birth certificate, a state spokeswoman said.

A Hawaii deputy attorney general gave the men information on the legal requirements to obtain such a document; the requirements are also posted on the Health Department’s website. The two men then left the office, department spokeswoman Janice Okubo said.

The two men showed Maricopa County Sheriff’s Office badges and identified themselves as Michael Zullo and Brian Mackiewicz, Okubo said. They are “authorized by the Sheriff of Maricopa County, who is conducting an official investigation,” a spokesman for the sheriff’s office said in an email.

Maricopa County Sheriff Joe Arpaio has been researching Obama’s residency status using a volunteer cold-case “posse,” but now has added a sworn deputy to the effort, The Arizona Republic reported Monday.

Zullo is a volunteer, the Republic reported, but Okubo said Mackiewicz presented a business card showing he is with the Threats Management Unit of the sheriff’s office.

Arpaio’s birth certificate investigation comes as the U.S. Justice Department is suing his office for alleged civil rights violations, including discrimination against Hispanics.

Separately, Arizona Secretary of State Ken Bennett, who says he is not a “birther,” said in a radio interview Thursday that Obama’s Arizona ballot status is in question unless Hawaii responds positively to his request under a Hawaii law regarding confirmation of birth certificates.

Hawaii Department of Attorney General spokesman Josh Wisch said Monday the department has been in touch with Bennett since Friday and that he would need to provide legal authority showing his office is “a governmental agency or organization who for a legitimate government purpose maintains and needs to update official lists of persons in the ordinary course of the agency’s or organization’s activities.”

Obama was born in Honolulu on Aug. 4, 1961. Birthers contend Obama was not born in the United States and thus not eligible to be president. The state released a copy of Obama’s long-form birth certificate last year, but that did not satisfy many birthers.

Bennett, a Republican who is reportedly considering a run for Arizona governor, said Friday he assumes he will get the confirmation he requested in March from Hawaii officials.