The decision by President Donald Trump to pardon former Arizona Sheriff Joe Arpaio over his criminal contempt conviction was wrong, the top-ranking Republican in Congress has said.
Republican House of Representatives Speaker Paul Ryan said that he did not agree with the decision.
Mr Arpaio, 85, was found guilty after he defied a court order to stop traffic patrols targeting suspected immigrants.
He said his conviction was "a witch hunt by the Obama justice department".
Mr Ryan is the latest senior politician to condemn the former policeman's release.
"Law enforcement officials have a special responsibility to respect the rights of everyone in the United States. We should not allow anyone to believe that responsibility is diminished by this pardon," his spokesman said in a statement.
Other prominent Republican critics include Arizona Senator John McCain and former Florida Governor Jeb Bush. Arizona's other Republican Senator Jeff Flake also condemned the move as did Democrats and human rights campaigners.
Mr Arpaio's lawyer Jack Wilenchik said that those critical of his pardon were wrong because he was unfairly prosecuted - there was no jury in his case.
The former sheriff was an eager supporter of Mr Trump's campaign to become president and backed tougher policies to combat illegal immigration.
In a statement announcing the pardon, his first, Mr Trump said: "Arpaio's life and career, which began at the age of 18 when he enlisted in the military after the outbreak of the Korean War, exemplify selfless public service.
"Throughout his time as sheriff, Arpaio continued his life's work of protecting the public from the scourges of crime and illegal immigration.
"Sheriff Joe Arpaio is now 85 years old, and after more than 50 years of admirable service to our nation, he is a worthy candidate for a presidential pardon."
The former policeman has said that he may consider running for political office again, despite his age.
He lost a bid for re-election in Arizona's Maricopa County in November 2016, after 24 years in office.
Mr Arpaio, born in Springfield, Massachusetts, could have faced six months in jail at his sentencing in October.
He served in the US military before he became a police officer - where he quickly acquired a reputation for his anti-immigration stance and tough enforcement tactics.