The state Attorney General’s Office is investigating whether advice from an agriculture industry group improperly tilted a state survey on wage rates for farm workers toward lower wages.

The agency requested documents and communications from WAFLA, formerly known as the Washington Farm Labor Association, on the survey specifically and in general on farm worker wages and the H-2A guest worker program.

WAFLA is cooperating, executive director Dan Fazio said in an email Friday.

“We are confident the Attorney General’s Office will be thorough and fair, and it will find that we have followed all laws, rules and regulations,” Fazio said. “We have nothing to hide.”

“I think it’s a positive step that they are looking into it,” said Joe Morrison, labor attorney with Columbia Legal Services, which was among several groups asking earlier this week for an investigation.

The date on the document request from the Attorney General’s Office shows that the civil investigation of a possible violation of the state’s unfair business practices law was launched in late December.

The survey, conducted by the state Employment Security Department, is used by the federal government to set wages for employment contractors, including guest workers under the H-2A program. WAFLA is the largest recruiter of H-2A workers from Mexico in the state.

Farm worker advocacy groups called for the investigation after Employment Security released a report just before Christmas highlighting how recommended answers from WAFLA had influenced grower responses and lowered reported wages compared with previous surveys.

WAFLA recommended reporting the guaranteed minimum hourly wages during harvest instead of piece-rate wages, which usually allow skilled workers to make much more.

Fazio said the state’s survey, which asked for rates during the busiest week of harvest, was designed to inflate wages, and reporting hourly wages was a fair way for growers to respond.

“That’s why what we hope to see is the documents,” Morrison said. “If in fact the growers were paying an hourly rate, then there’s no problem. But if the 40 or so growers whose responses (to the employment department) said matched WAFLA’s were in fact paying piece rates during harvest, that matters.”