Marler Clark, a prominent Seattle food-safety law firm, filed suit against Kern County nut processor Paramount Farms, whose raw almonds are the target of a greatly expanded product recall.

The Food and Drug Administration says nuts potentially tainted by salmonella bacteria likely are in a wider array of packages and stores than first announced.

The FDA has tentatively linked 18 cases of food poisoning to raw almonds from Paramount Farms of Lost Hills in Kern County, the state’s largest almond grower. Potentially related illnesses still are being investigated.

Paramount has expanded its recall to 13 million pounds from 5 million pounds. It also said that it immediately would start pasteurizing all almonds before they are shipped. Costco Wholesale Inc., who sells the nuts, mailed recall warnings to 780,000 members nationwide who bought almonds in recent months. They will also be alerting international customers who also may have tainted almonds. Some of the raw nuts were shipped to Mexico, Japan and six other countries.

Roasted, blanched, slivered and sliced almonds are not part of the recall because the processing kills bacteria.