Western Union Co, Englewood, Colorado, won a court ruling that bars Arizona from seizing funds sent by customers in other states to Mexico as part of a probe into drug and immigrant smuggling.

Arizona Atty. Gen. Terry Goddard obtained a warrant in September to intercept transfers of $500 or more between 28 U.S. states and 26 places in Sonora, Mexico, so he could look for criminal ties. The Superior Court in Maricopa County ruled that Arizona lacked authority over transactions from other states or enough cause to suspect wrongdoing. Goddard, however, promised to appeal. The decision does not affect the legality of similar warrants that Goddard’s agency uses to seize money sent directly to or from Arizona

Western Union had contended that the program was unconstitutional and threatened its relationship with customers. The warrants forced the intended recipients of money transfers to call and talk to a police officer on a financial task force, who decided whether a transfer was legitimate.