PHOENIX – A federal judge ruled Wednesday that Arizona authorities can enforce the most contentious section of the state's immigration law, which critics have dubbed the "show me your papers" provision.

The ruling by U.S. District Judge Susan Bolton clears the way for police to carry out the requirement that officers, while enforcing other laws, question the immigration status of those they suspect are in the country illegally.

The provision has been at the center of a two-year legal battle that resulted in a U.S. Supreme Court decision in June upholding the requirement, ruling against the Obama administration, which filed the initial challenge.