An eight-year-old kidnapped boy has been killed and his body hacked to pieces allegedly by his cousin who is said to have claimed that he was left with no option after the child became "unmanageable" in his custody.

Ranajay Thakur, 35, who has been arrested on the charges of abducting and killing Vishal Sharma, admitted to the crime after the child's remains were found, police said.

Parts of the brutalised body of Vishal, who was abducted on Wednesday afternoon, were found on Thursday night near a vat, a few metres from his home on BL Roy Road in Howrah's Salkia. The body parts were found after residents spotted a stray biting a hand.

Terrified residents alerted the police, who started a search but failed to find the rest of the body.

On Friday morning, some strays dug up a beheaded body in school uniform from under a mound of trash in the vat. "The body has been identified as that of Vishal's," said an officer of Golabari police station, where Vishal's father Ram Vilas lodged a complaint after getting a call demanding Rs 50,000.

The police said Vishal's cousin Ranajay Thakur, 35, was arrested on Wednesday after he turned up in Calcutta's Burrabazar to collect ransom.

"Ranajay kept misleading us by saying that he had sent Vishal to an acquaintance in Jharkhand's Hazaribag," an officer said.

Ranajay is the son of Vishal's paternal aunt.

"Ranajay had met Vishal at 1pm outside Vikram Vidyalaya in Salkia, where the child studied in Class III. He told Vishal that Ram Vilas was at his house waiting for the kid. He then took Vishal to a hideout in Pilkhana, around a kilometre from the child's house," the officer said.

Ranajay is said to have told the police that Vishal was fine for some time after he was taken to the hideout.

"He started getting restless after a couple of hours and wanted to go back to his parents. When I scolded him, he started crying. I got frightened because his cries could have attracted people's attention. He was becoming unmanageable. I had no option but to kill the boy," an officer quoted Ranajay as saying.

Ram Vilas said his son would usually be home from school by 1.30pm. "On Wednesday, when he failed to return even by 3pm, we started getting worried. Around 3.30pm, I received a call on my mobile phone. The caller claimed he had kidnapped my son and demanded Rs 50,000 as ransom. Some of my friends advised me to go to the police," the father recounted.

The caller told Ram Vilas, who runs a salon in Salkia, to wrap Rs 50,000 in newspaper and keep it in a basket in a temple near Satyanarayan Park in Burrabazar around midnight. Ram Vilas immediately alerted cops, who accompanied him to the trade hub.

Within a few minutes, a man whose face was partially covered with a black scarf appeared near the basket. Just when he was about to pick up the bundle, the cops nabbed him.

Ram Vilas, who was with the cops, recognised Ranajay.

On Thursday night, a police team left for Hazaribag with Ranajay and Ram Vilas in search of Vishal. "He was hoping if the body was not found, he would be let off," the officer said.

The same night residents of Pilkhana alerted the police after they spotted a stray roaming around with a human hand dangling from his mouth.

Krishnakali Lahiri, the deputy commissioner of police (north), Howrah, said the police were trying to find Ranajay's accomplices.

Murder pre-planned

Mohammad Shahnawaz, the man arrested in connection with the death of a Maharashtra businessman, had planned to kill him even before he reached Calcutta, police said on Friday.

Immediately after arresting Shahnawaz late on Thursday, the police had said he had shot Sailesh Sampat Rao Shinde thrice.

Shahnawaz, a labour contractor by profession, has told the police that Shinde had refused to return him Rs 22 lakh, an officer said.

"He was prepared to kill Shinde. He had bought a gun to eliminate the 41-year-old even before the trader had reached Calcutta. Shahnawaz was the last person to meet Shinde at the guest house. They both left around 10.30pm on Wednesday," said an officer of the homicide department.

Shinde was found riddled with bullets sitting on a stone slab in Mianjan Ostagar Lane near Park Circus.

Preliminary investigations have revealed that Shahnawaz alone had shot Shinde thrice and left him to die in front of 30 Mianjan Ostagar Lane. Shahnawaz lives in the adjoining house.