(CNN) - Utah officials are trying to determine whether government data were used to compile a list of more than 1,300 alleged illegal immigrants that included contact information, Social Security numbers and pregnancy due dates.
A state investigation is focusing on the Utah Department of Workforce Services, Gov. Gary Herbert's office said Thursday, because all information on the list is contained within that agency's database. Information from the investigation may be turned over to state prosecutors, a statement from the office said.
"They have very strong leads, first to indicate that it came from that agency and now it's just a process of drilling into the information a little deeper," governor's spokeswoman Angie Welling told CNN-affiliate KSTU.
The list was anonymously distributed to media and government offices across the state, the affiliate reported. An accompanying letter from "Concerned Citizens of the United States" insisted that those on the list should be deported immediately. Watch 
Welling told the affiliate that if the investigation reveals any state employees were responsible for the leak, those people have no place working in the state government.
"When people do business with the state of Utah of any kind, they deserve to know that the information they provided is protected. That's the first issue. Then, immigration is the second issue," she said.
Earlier Thursday, a group of Latino activists told reporters that the list had sparked widespread fear.
"Our community is very concerned, very worried about it," said Tony Yapias with Proyecto Latino de Utah. "I would say they have been terrorized, many of them. People are just afraid of what's happening."
Those named on the list are even more frightened, said Jesus Ramos with the Utah Coalition of La Raza.
"For these 1,300 people, unfortunately that fear has escalated," he said. "There's an arrest warrant out, essentially. That fear never goes away."
Utah Minuteman Project co-chairman Eli Cawley told CNN-affiliate KSL that he had some concerns about privacy and how the names were procured, but he would have released a similar list if he could have.
"If it were a reliable list and it had come from a source that was acknowledged and vetted, then yes, I would absolutely support something like that," he said.
Yapias told KSL that he suspected an anonymous call he received June 30 from a woman claiming to be a state worker frustrated with illegal immigrants may have something to do with the incident.
Dave Lewis, a spokesman for the Department of Workforce Services, told KSL that investigators were poring over electronic records.
"We'll be looking for red flags, patterns, possibly personnel that don't have any business reason for being in that case," he said.
Utah State Sen. Luz Robles told KSTU that the state's investigation would determine how the data got out.
"I don't care how you feel about immigration. I've heard from my constituents. They want to make sure that their information is protected, so this goes beyond immigration. It's an attack on the integrity of your privacy," she said.