Washington’s attorney general said he will still seek penalties against a food-industry group that recently identified donors who contributed to oppose a food-labeling initiative.

Attorney General Bob Ferguson will pursue a suit filed last week against the Grocery Manufacturers Association. He has accused the group of collecting the cash in a manner that shielded the identities of the companies.

The Grocery Manufacturers Association has since identified about three dozen companies behind a combined $7.2 million contributed to help defeat Initiative 522, which would require labeling on genetically modified foods in Washington.

Ferguson said in a statement that the case involved concealing a record-setting amount of contributions and there must be sanctions for violating the law.

No court date has been set.

I-522 has shaped up to be one of the costliest initiative fights ever in Washington state, with many parts of the food industry contributing large chunks of cash to oppose the measure.

PepsiCo, Coca-Cola and Nestle each contributed more than $1 million to the Grocery Manufacturers Association’s effort to oppose the measure, according to records filed with the state Public Disclosure Commission last week.

Supporters say consumers have a right to know whether foods they buy contain genetically engineered ingredients. Opponents say it would cost farmers and food processors and that such a label implies the food is somehow less safe.