A U.S. District court has struck down an Arizona law enacted in 2005 cracking down on immigrant smuggling.

Federal judge Susan Bolton on Friday struck down Arizona's previous immigrant smuggling law on the grounds that the state's law conflicted with federal government laws governing immigration.

Arizona state officials enacted the immigration smuggling law in response to growing anger from constituents surrounding the activity around Arizona, which was considered to be the largest immigrant smuggling hub in the U.S. at the time.

Controversial Maricopa County Sheriff Joe Arpaio used the law often during his crackdown on undocumented immigrants, and the state statute was one of several tough immigration laws that was partially credited for triggering a sharp decline in the state's undocumented immigrant population, which fell from its peak of an estimated 560,000 undocumented immigrants in Arizona in 2008.

However, Bolton ruled that Arizona's immigrant smuggling law interfered with federal authorities' rights to prosecute smuggling crimes. The law was taken to court by the Obama administration as part of its challenge to Arizona's controversial 2010 immigration law.

The immigration law struck down this week drew much attention after more than 2,000 immigrants paying smugglers to sneak them into the U.S. were charged with conspiracy to smuggle themselves across the border. Critics blasted the decision, claiming that the law was intended to punish smugglers, not those who paid to enter the country. In 2013, another federal judge banned the tactic from being used by Arpaio's office. That same year, another judge ruled that Arpaio's office has been racially profiling Latinos during patrols.

While federal courts have been curbing most of Arizona's stringent immigration policies, some particularly contentious policies have been upheld, among the most controversial being a section of the 2010 state immigration law that required police to check a person's immigration status under certain conditions. Civil rights groups are looking to challenge the law themselves in federal court.