NORTH COUNTY -- Groups protesting unchecked immigration have recently focused their efforts on day-labor sites around North County, averring that employers who hire the workers are breaking federal laws.

But immigration authorities and immigrant rights advocates say the law is not that clear.

"Some of them are (breaking the law) and some of them are not," said Lauren Mack, a spokeswoman with the U.S. Immigration and Customs Enforcement in San Diego.

Anti-illegal immigration activists, including those who belong to the San Diego Minutemen and their allies, say that most day laborers -- primarily men who stand on corners looking for temporary work -- are illegal immigrants and that hiring them is a crime under federal law.

The Immigration Reform and Control Act of 1986 prohibits people without legal documentation from working in the United States. It generally requires employers to verify their workers' immigration status, but there is an exception.

The law does not include "casual employment by individuals who provide domestic services in a private home that is sporadic, irregular or intermittent," it states.

Immigrant rights activists say that means residents who hire day laborers for domestic work, such as mowing the lawn or moving furniture, do not have to verify the workers' immigration status.

That is "the type of arrangement which covers so many of the day laborers who are contracted by homeowners and renters for odd jobs over the weekend," said Claudia Smith, a longtime immigrant rights activist with the California Rural Legal Assistance Foundation.

Opponents say most day laborers are hired not by individuals but by small companies trying to skirt the law.

Attorney Gary Kreep said that most day laborers are hired by companies who know the workers are in the country illegally, but hire them anyway to avoid paying taxes and save money. Kreep is executive director of the Ramona-based United States Justice Foundation, a legal organization that often represents Minutemen activists.

"I think it's the exception rather than the rule that it's a little old lady or a little old man that is hiring the day laborers," Kreep said.

Companies are required to verify workers' immigration status, even if they are hired at day labor sites, Mack said.

Earlier this year, the founder and a vice president of Golden State Fence Co., one of California's largest fence-building companies, were sentenced to probation and large fines for knowingly hiring illegal immigrants.

Immigrants working in the country without proper documentation can face deportation.

According to a study released last month, 80 percent of the estimated 40,000 day laborers in California are working in the state without legal documentation, such as visas or work permits.

About 68 percent of them are from Mexico, 29 percent of them are from other parts of Latin America and about 3 percent were born in the United States.

The number of people who stand on street corners looking for work make up 0.02 percent of the state's total work force, according to the study by the Public Policy Institute of California, a San Francisco-based private research organization.

Those surveyed said about 51 percent of people who hire day laborers are private individuals. Contractors made up 43 percent of people who hire the laborers, and private companies comprised about 3 percent.

Smith said those figures may vary by location and day of the week. She said that on the weekends, when recent protests from anti-illegal immigration activists have driven away many laborers, workers are more likely to include legal immigrants looking to supplement their incomes from regular jobs.

Groups that oppose day-labor sites disagree.

Ira Mehlman, a spokesman for the Federation for American Immigration Reform, a group that advocates for stricter immigration policy, said day-labor sites attract illegal immigrants.

"It creates a magnet for illegal immigration," Mehlman said. "People come here because they see opportunity to make more money than they do in their own country."

The federation offers advice on its Web site for "confronting illegal day labor issues" by protesting at hiring sites.

In North County, such protests in Vista led to a law adopted by the City Council requiring would-be employers to register with the city before hiring day laborers. The ordinance was challenged by Latino and civil rights groups, including the American Civil Liberties Union.

The law was modified as a result of the lawsuit, but it remains in place.

Anti-illegal immigration activists have more recently focused their protests on St. Peter's Catholic Church in Fallbrook, which allows day laborers to gather on its property. The protesters claim the church is also breaking federal laws by helping illegal immigrants find work.

Smith said the church is not violating the law.

"Only if the church was referring day laborers for a fee would it be required to itself verify the immigration status of the individuals who seek work there," she said. "Instead, St. Peter's involvement is limited to offering a bench, some shade, a toilet, drinking water and breakfast."

One thing is clear, Mack said.

While a private citizen hiring a day laborer may not be breaking immigration laws, "it is illegal (for an immigrants or visitors) to work without authorization," she said.

The difficulty for those who claim that hiring a day laborer is a crime is proving that the person is not authorized to work, she said.

"It's not even clear if the person is here legally or illegally," she said.

Contact staff writer Edward Sifuentes at (760) 740-3511 or esifuentes@nctimes.com.