Maricopa County Sheriff Joe Arpaio's immigration and crime sweeps are being targeted in a lawsuit that alleged his officers have racially profiled countless Hispanics.

The attack on the sweeps alleged the officers based some traffic stops on the race of Hispanics who were in vehicles, had no probable cause to pull them over and made the stops so they could inquire about their immigration status.

"From what we have been hearing on the ground, (Arpaio) has been violating people's civil rights left and right," said Kristina Campbell, an attorney for the Mexican American Legal Defense and Education Fund, one of the groups pushing the allegations. The allegations were filed Wednesday as part of an existing lawsuit.

While Arpaio defends the sweeps in Phoenix, Guadalupe, Mesa and other cities as crime suppression efforts, he has been criticized heavily for conducting the crackdowns in heavily Hispanic areas and has fueled a backlash from some officials who consider the operations to be an unwanted intrusion into their communities.

Sheriff's spokesman Capt. Paul Chagolla declined to comment on the lawsuit's contents, but said the agency doesn't racially profile people and that the sweep allegations were an attempt to refresh a civil case against the sheriff. "This is not a new lawsuit," Chagolla said.

Allegations about the sweeps were added to a lawsuit, filed in December, that alleges a Mexican man in the country legally was unnecessarily detained by a deputy investigating the man's immigration status.

Among Arizona's local police bosses, Arpaio has taken the most aggressive approach to cracking down on illegal immigration. His efforts include creating a special immigration unit, arresting more than 1,000 illegal immigrants under a state smuggling law and setting up a hot line to report immigration violations.

The latest court filing alleged Arpaio, who has 160 patrol and jail officers trained in enforcing federal immigration law, has let deputies and posse volunteers perform immigration duties when they weren't trained to do so.

The federal agency that gave the officers the special training has said the sheriff has stayed within the bounds of its training agreement.

Phoenix Mayor Phil Gordon, who disapproved of the sweeps in Phoenix and has become Arpaio's most prominent critic, has asked for a federal investigation of Arpaio for possible civil rights violations.

The U.S. Justice Department has declined to say whether it would investigate the sheriff.