The child, Fatehveer Singh, was brought to the PGI Hospital in Chandigarh, some 130 km from the accident spot, soon after he was retrieved from the well, officials said.
On admission, he had no pulse, no respiration and no cardiac activity. Hence, the child was declared brought dead, the Postgraduate Institute of Medical Education and Research (PGI) said in a statement.
Postmortem findings are suggestive that death occurred a few days back, it added.
Expressing anguish over the tragic death of the toddler, who failed to survive his 108-hour ordeal in a borewell in Bhagwanpura village of Sunam, Punjab Chief Minister Amarinder Singh on Tuesday ordered the closure of all open borewells across the state.
The Chief Minister, while ordering a detailed inquiry into the incident, has sought reports from the Deputy Commissioners on all such existing open borewells, with a direction to take immediate corrective action to prevent the recurrence of such incidents.
He asked the Disaster Management Group headed by the Chief Secretary to finalise a set of standard operating procedures to check and prevent such incidents.
The group, which had been constituted to tackle natural calamities, has also been asked to study the inadequacies, if any, in the relief operations, and give recommendations to ensure better and quicker operations in the future in case of any such or similar man-made disaster.
He said the district administration had mobilised and initiated rescue operations within minutes of receiving information of the child falling into the borewell at 4.15 p.m. on June 6.
As the child was retrieved, his grandfather Rohi Singh told the media on the spot: "Why was he taken to the hospital when he is no more."
He claimed that the body of the child had grievous wounds. "He was pulled out (of the borewell) by using strings."
A health worker in the PGI's mortuary told reporters that the child's body was badly decomposed.
The boy was retrieved by personnel of the National Disaster Response Force (NDRF).
Sangrur Deputy Commissioner Ghanshyam Thori said it was one of the toughest operations carried out by the NDRF.
Lack of expertise and technical snags one after another were blamed for the delay in the massive rescue operation.
As per reports, though NDRF personnel were able to tie a knot around both the child's wrists in less than 10 hours of arrival, the narrow diameter of the pipe caused the kid to get stuck, forcing them to give up this method.
All possible technical support was also provided by the district administration but it took 46 hours to dig a parallel pit and lay pipes against its wall to prevent it from caving in, the government said.
But problems with the angle at which the pipe was going in further obstructed the operation, necessitating some horizontal digging also.
Meanwhile, tension prevailed among villagers in Sangrur over the inability of the state government to retrieve the toddler in time.
Thousands of angry protesters blocked the road leading to Bhagwanpura village in Sunam sub-division, some 15 km from the district headquarters at Sangrur, where the incident occurred.
On March 22, a one-and-a-half-year-old boy, who fell into a 70-feet narrow borewell in Haryana's Hisar district, was rescued after a 48-hour operation.
In July, 2006, Army engineers in Haryana's Kurukshetra town had rescued a little boy trapped in a 60-feet well for two days.
( With inputs from IANS )