MEXICO CITY (AP) — A U.S. senator is urging an investigation into whether two guns recovered at the scene of a shootout in Mexico that killed a beauty queen were part of the U.S. gun-smuggling operation known as "Fast and Furious."

Sen. Charles Grassley says he received tracing information on an FN Five-seven pistol and an AK-47 rifle recovered in Mexico's Sinaloa state after a Nov. 24 shootout killed at least three people, including 20-year-old beauty queen Maria Susana Flores Gamez.

He says one weapon was purchased by the key straw buyer in "Fast and Furious" and the other apparently by the main ATF agent who ran the botched operation, in which agents let suspected straw gun buyers walk away from shops with weapons in hopes of catching drug kingpins.