Police officials in Noida, a satellite city of the Indian capital, said that they were checking connections between the two men arrested for the killings and a local doctor, after parents questioned why no torsos had been found among the remains.

"There was a suspicion that a neighbour who was a doctor might be involved in the human organ transplant racket," senior Noida police official Saumitra Yadav told AFP on the cordoned-off road leading to the suspects' house.

Mohinder Singh, a dealer in earth-moving equipment and who owns the property next to the sewage drain where the skeletons were found, and his domestic help Satish were arrested after the grisly find was made Friday.

"There is no conclusive evidence. We found skulls but torsos are comparatively less," said Yadav, adding that their absence could be because of decomposition.

Police on Monday raided a nearby medical centre owned by the doctor neighbour, the Indian Express newspaper reported.

Diggers were still clearing debris dug up from around Singh's house Tuesday as over 100 police and dozens of reporters attended the scene.

The domestic help confessed to luring and killing 10 children with sweets and toys, Yadav said, while Satish's employer, who has denied his involvement, was also charged with rape, murder and concealment charges.

The murders came to light when police picked up Satish for questioning for his suspected involvement in the disappearance of a 16-year-old girl.

A maid who worked in the house and who lives in the neighbourhood from where the majority of the children vanished has also been detained for questioning.

The victims, mainly girls, were the children of labourers living in shanty clusters near the house where the arrested men lived, and furious relatives have accused police of failing to act after the disappearances were reported.

"They came two or three times then they stopped coming. They said she eloped," said Sulata Haldar, whose 13-year-old daughter Bina was among the first to disappear in 2005.

"They said, 'We will keep looking for her, but you also look'," recalled Haldar.

Haldar was taking Bina to work with her when the girl complained of feeling sick. She left her daughter near the tall water tank next to Singh's house to walk home and never saw her again.

On Friday, among the remains unearthed from the drain, she identified the loose green drawstring pants Bina was wearing the day she disappeared.

The shanty dwellers, most of them poor migrants from eastern West Bengal state, say dozens of their children -- most put the figure at 40 -- disappeared in the last two years, many of them from the near the same water tank.

"The police told me 'you Bengalis have so many children, then you can't take care of them.' They said 'she's a pretty girl, you have no idea what she must be up to'," said distraught Vandana Sarkar.

Sarkar's 20-year-old daughter, Pinky, disappeared in October and police officer Yadav confirmed she was among the official victims.

"I saw her white pants completely drenched with blood," said Sarkar, holding a photograph of Pinky at age 17, round-faced and pretty in a sari, with her hands decorated with henna.

"I cannot even begin to imagine what they must have done to her."