Self-styled 'toughest sheriff in America' is also its most racist

Joe Arpaio, sheriff of Maricopa County, Arizona, is accused of mistreating Latino prisoners in his care (Getty Images)

He likes to call himself "America's toughest sheriff" – but a report by the US government suggests that, against stiff opposition, he is probably its most racist sheriff, too.

Joe Arpaio, a lawman from Arizona who has made headlines across the world with his tough approach to illegal immigration, stands accused of running a department in which racial-profiling and discrimination are endemic.

The US Justice Department found that Arpaio and his officers harrassed and illegally arrested hundreds of Latino men and women, and then abused them in prisons.

Over the past three years, they also failed properly to investigate 432 cases of sexual assault and child molestation, apparently because the victims were largely Hispanic.

In Phoenix, where Sheriff Arpaio's office is based, Latinos were four times more likely to be stopped for motoring offences than white people. Once in jail, inmates who failed to understand commands in English were subjected to solitary confinement for 23 hours a day.

A review of internal emails and arrest records found cases of one Latino suspect being intentionally hit by a police patrol car, and another driver being imprisoned for 13 days for not using his indicators before turning.

Memos written by Mr Arpaio's deputies talked about cracking down on people from "Mexifornia". In the county prison, Latinos were derided by officers as "wetbacks", "Mexican bitches" and "stupid Mexicans".

Mr Arpaio, 79, who was first elected sheriff of Maricopa County in 1992, has achieved notoriety by dressing prisoners in pink underwear and making them live in tents, despite daytime temperatures in the region that can top 43.3C (110F). He has also filmed reality television programmes with the actor Steven Seagal.

The Department of Homeland Security responded to the report, published on Thursday, by revoking his authority to detain people on immigration charges.

In response, Mr Arpaio told a press conference: "Don't come here and use me as a whipping boy for a national and international problem."