Website ORM claimed that Kelvin Santos stopped breathing during treatment for pneumonia at a hospital in Belem, northern Brazil.
He was declared dead at 7.40pm on Friday and his body was handed over to his family in a plastic bag.
The child's devastated family took him home where grieving relatives held a wake throughout the night, with the boy's body laid in an open coffin.
But an hour before his funeral was due to take place on Saturday the boy apparently sat up in his coffin and said: "Daddy, can I have some water?".
The boy's father, Antonio Santos, said: "Everybody started to scream, we couldn't believe our eyes. Then we thought a miracle had taken place and our boy had come back to life.
"Then Kelvin just laid back down, the way he was. We couldn't wake him. He was dead again."
Mr Santos rushed his son back to the Aberlardo Santos hospital in Belem,where the doctors reexamined the boy and confirmed that he had no signs of life.
He said: "They assured me that he really was dead and gave me no explanation for what we had just seen and heard."
The boy's family decided to delay the funeral for an hour in the hope that he would wake up again, but ended up burying him at 5pm that day in a local cemetery.
Convinced that his son was victim of medical malpractice, Mr Santos has now registered a complaint with the police who have launched an investigation
He said: "Fifteen minutes after rushing him away for resuscitation, they came and told me he was dead and handed me his body. Perhaps they didn't examine him properly. Dead people don't just wake up and talk. I'm determined to find out the truth."
The local state department today confirmed the boy had been admitted to hospital in a critical condition and was declared dead after suffering cardiac-respiratory failure.