“This kind of treatment to poor and innocent people generates hatred toward the government and puts a distance between the public and the government,” said Hajji Amanullah, a neighbor of Mr. Ghani and Mr. Ali. “If people don’t go to the Taliban, at least they will keep hatred in their hearts for the police.”

He added: “We did not experience such a barbaric event during the time warlords were in charge in Kandahar, when there was no judicial system, no legal system. Now, in the presence of civil society, human rights and court systems, such unlawful things are taking place and everyone is silent.”

Mr. Ali was arrested last Tuesday after the local police received a complaint that he had been fighting with a neighbor. Mr. Ghani, his father, said he went to check on him at the police station each day, but was not allowed to see him. The police repeatedly told him his son was fine. Then, on Saturday, the story changed.

Mr. Ghani was abruptly told his son was dead.

“I said, ‘How can this be? He was young he was not sick or feeble or disabled,’ ” Mr. Ghani said. “They said, ‘We don’t know, we were keeping him in a container, and when we opened the door to feed him lunch, he was dead.’ ”

He added that the police told him, “Go collect your son’s body from the hospital and bury him and don’t say anything and we will help you.”

“When I found him in the morgue,” Mr. Ghani said, “I saw he was beaten up and strangled to death. The signs of torture could be seen on his body: His buttocks and back had been beaten with cable rods, and there was a clear, deep line on his neck that showed he had been hanged.”

Doctors at Kandahar’s Mirwais Hospital would not respond when asked what the man appeared to have died of. But a hospital worker who spoke on condition of anonymity, out of fear of reprisal by the police, said: “We receive dead bodies who have been dumped after killing. Sometimes the police are bringing them and sometimes ordinary people.

“This is not the only case.”