Police say Alam Khan confessed to his crime with an "utter lack of remorse".
A 24-year-old man from Uttar Pradesh has confessed to stabbing his father's killer to death and chopping his body into 12 pieces, one for every year since his father was murdered, media reports have said.
Alam Khan was 12 years old when he saw his father being murdered by a family friend in 2003. He had secretly planned his revenge ever since and finally seized his chance last week when he invited the killer over for a drink.
After getting Mohammad Rais drunk at his home in Moradabad district, Khan knifed him to death before using a hammer and hacksaw to dismember the body, he told reporters on Monday after his arrest.
He and an accomplice then packed the body parts into plastic bags which they threw into a river. When the bags washed up on the river's banks, police were able to identify Rais from a surgery scar on his torso.
Khan was arrested after witnesses recounted how Rais had last been seen visiting his home, and he confessed to the crime.
"I played some music at full volume and cut his body into 12 pieces," Khan was quoted as saying by the Times of India.
He had never told anyone about the identity of his father's alleged killer and had instead waited for 12 years to "realise his dream" of taking revenge, the police have said. He was "happy it was now done," he told his interrogators.
Police Superintendent Ram Suresh Yadav told the newspaper that Khan had confessed to his crime with an "utter lack of remorse".
The murder weapons, including the hammer and hacksaw, were recovered from his home.