The federal raid of a Colorado-based meat-packing company exposed flaws in South Carolina’s efforts to curb illegal immigration, critics said Wednesday.

A bill being drafted in the S.C. Senate would require companies to enroll in a federal program to verify employee identification before doing business with the state.

Lawmakers had hoped to rein in illegal immigration by requiring contractors and subcontractors to enroll in the program.

But the company raided Tuesday had been participating in the program since 1997.

“This means we may not be accomplishing anything,” said Sen. Ronnie Cromer, R-Newberry, a member of a Senate subcommittee working on immigration.

The federal verification, known as the “Basic Pilot Program,” is the foundation of South Carolina’s proposed legislation. The program also is a key part in local government efforts to regulate immigration.

Lawmakers will have to study what happened to Swift & Co., Cromer said, but the Basic Pilot Program will stay in the proposed bill.

“We really don’t have anything else to be honest with you,” Cromer said. “That’s all the government’s got.”

Tuesday, Immigration and Customs Enforcement agents detained 1,282 workers at Swift & Co. packing plants in six states, forcing the company to run at reduced levels. The company does not operate in South Carolina.

Immigration officials in Washington said the raid was part of a crackdown on an identity theft scheme. Of the workers detained, 1,217 were being held on immigration charges alone and 65 were facing identity theft or other criminal charges.

Homeland Security Secretary Michael Chertoff said the raid uncovered a “disturbing front” in the war against illegal immigration because it shows immigrants are using the identities of U.S. citizens to obtain jobs.

“Violations of our immigration laws and privacy rights often go hand in hand,” Chertoff said. “Enforcement actions like this one protect the privacy rights of innocent Americans while striking a blow against illegal immigration.”

Swift never knowingly hired undocumented workers, president Sam Rovit said, and the company volunteered for the Basic Pilot Program.

Under the Basic Pilot Program, companies enter an employee’s name and Social Security number into an automated database within three days of the hiring.

The program compares the information in Social Security Administration and Department of Homeland Security databases to determine whether the employee is eligible to work.

Employees have a right to contest findings, but a company must fire a worker if he is not authorized to work.

The Government Accountability Office has reported flaws within the Basic Pilot Program. In June, the agency told a U.S. Senate subcommittee on immigration that the program had weaknesses, such as its inability to detect identity fraud. The program’s database is often out of date, and it could not handle a large increase in participants.

Fred Manning, an employment lawyer with Fisher and Phillips in Columbia, advises clients not to participate because they must waive certain rights as private businesses. He says the program brings federal attention to companies that enroll.

“The Basic Pilot Program, which is voluntary, is really a mechanism for the Department of Homeland Security to begin winnowing down targets for raids,” Manning said.

Ken Carey, president of Agil Staff, a Columbia employment agency specializing in bilingual workers, said the program has uncovered undocumented workers applying for jobs at his office.

But it also falsely has identified a legal worker as being unauthorized, Carey said. Often, simply telling applicants about the program is enough to weed out undocumented workers.

It was “scary” to hear about Swift’s raid, Carey said, but he plans to keep using the pilot program.

Sen. Jim Ritchie, R-Spartanburg, wants the Senate to forge ahead and require businesses to enroll in the Basic Pilot Program. If a better program is developed, he would support measures to require its use.

“There’s no guarantee, but it’s the best we have,” Ritchie said. “What we’re saying is, the state is going to do its level best to say it’s only working with legal contractors and subcontractors.”

Reach Phillips at (803) 771-8307.The Associated Press contributed.