(November 4, 2003) - (Bentonville-AP) -- Bentonville-based Wal-Mart said today that it has received a target letter from the U-S Attorney's Office that the world's largest retailer allegedly violated federal immigration laws. On October 23rd, federal agents arrested about 250 alleged illegal workers in a 21-state sweep of Wal-Mart stores. Federal prosecutors in Pennsylvania are handling the case. The company has pledged its full cooperation. Wal-Mart spokeswoman Mona Williams says the company expects to get a full chance to explain its side before the government decides whether to lodge any charges. The investigation focuses on contract floor cleaning companies that did work at Wal-Mart stores. A raid on October 23rd netted 250 arrests among 60 stores in 21 states. Ten of the people arrested were Wal-Mart employees hired as the company continued a move to bring its floor cleaning in house.