Arizona Sheriff Joe Arpaio has been sued by the U.S. Department of Justice for allegedly refusing to cooperate with investigations into possible civil rights abuses he may have committed against Mexican immigrants.

The Justice Department claims that Arpaio repeatedly ignored a year's worth of requests for documentation regarding his use of several million dollars of federal funding, as well as requests for tours of his facilities and interviews with his staff.

"The actions of the sheriff's office are unprecedented," Thomas E. Perez, assistant attorney general for the department's civil rights division, said in a statement. "It is unfortunate that the department was forced to resort to litigation to gain access to public documents and facilities."

Arpaio, who claims to be America's toughest sheriff, says that he is not intimidated by the lawsuit and denies the lack of cooperation, saying that just last week his lawyers had agreed to let the Justice Department tour his facilities.

"They smiled in our faces and then stabbed us in the back with this lawsuit," Arpaio said. "The Obama administration intended to sue us all along, no matter what we did to try to avert it."

The suit is the second filed by the Justice Department regarding Arizona's immigration policies.

In July, the department filed suit against an anti-immigrant bill passed by Arizoina in April which would allow law enforcement officers to demand documentation from immigrants at a moment's notice.

Later that month, a district judge in Arizona placed an injunction on the law saying that it would do more harm than good and put an unfair burden on legal immigrants.

Members of the faith community have clamored for the federal government to implement a comprehensive reform of the nation's immigration policies, but partisan divisions have slowed the process.

President Obama and Congressional democrats have declared their commitment to passing reform legislation and claim that GOP opposition is what's preventing progress.

Prominent Republican leaders, including Senator John McCain, have said that securing the U.S.-Mexico border must take place before reform legislation is considered.