WASHINGTON - Justice Department and federal immigration officials say they notified the Department of Labor in advance of an immigration raid in Postville, even as labor officials claim otherwise.

The differing opinions were revealed in letters to Rep. Bruce Braley, D-Iowa. The congressman released them on Thursday.

Braley said he is concerned about the possible impact the raid has had on ongoing labor investigations at Agriprocessors, the kosher meat processing plant raided by federal immigration agents on May 12.

It remains unknown how the raid affected any labor law or child labor investigations.

"Upholding immigration laws and ensuring worker safety are both vitally important to the people of Iowa, and one should not come at the expense of the other," Braley said.

The Department of Labor stated the "complexion" of its investigation had changed because of the raid, but provided no further details, citing an ongoing investigation.

ICE spokesman Tim Counts said the Department of Labor's law enforcement arm, Office of Inspector General, participated in the raid on Agriprocessors.

But the Department of Labor said in its letter that it first learned of the raid through news reports and that none of its agencies received advance notice of the raid.

The letter, signed by Kristine Iverson, assistant secretary of labor for Congressional and intergovernmental affairs, said that after hearing of the raid, one of its agencies "intervened to ensure that workers received their last paychecks."

"It sounds to me like a frustrated agency official is writing that letter," Braley said.

The congressman said he requested more details on the communications Justice and immigration officials say they had with the labor department.

State labor officials, conducting their own inquiry into Agriprocessors, said the raid helped their investigation.

Iowa Labor Commissioner Dave Neil of La Porte City said even though the raid interrupted their investigation into child labor and wage violations, it emboldened workers to speak to investigators.

"As the result of the raid, more people were willing to come forward and talk. Quite frankly, it just made things come to light a lot quicker," he said.

Neil said the child labor investigation should be completed in the next few weeks.

An investigation into the wages paid at Agriprocessors is just under way, he said. With only one wage investigator, he said determining if there is a case will take time.

Contact Jens Manuel Krogstad at (319) 291-1580 or jens.krogstad@wcfcourier.com.