Mexican human rights authorities say five men detained in the killings of two agents and a car-bomb attack in Ciudad Juarez were tortured by federal police to confess their roles in the crimes.
The National Human Rights Commission said Sunday the country must investigate six federal officers and a doctor who didn't report signs of severe beating.
Police had accused one man of being a lookout in a July 2010 car-bomb attack. They had also accused the five men of killing two police officers.
Police have dropped the accusations, but the men remain in jail on drugs and weapons charges.
Federal police said the men were members of the La Linea gang when they were arrested in August 2010 in the border city.