Rescuers have found the body of a two-year-old boy who fell down a well on January 13 in southern Spain after an unprecedented rescue operation fraught with glitches which had kept the country on tenterhooks.

Hundreds of people had been working round-the-clock under the media glare to try to reach Julen Rosello, who fell down a narrow shaft which is more than 100 metres (330 feet) deep while his parents prepared a lunch in Totalan, a southern town near Malaga.

"Unfortunately at 1:25 am the rescue team reached the spot where they were looking for Julen and found the lifeless body of the little one," the central government's representative in the southwestern region of Andalusia, Alfonso Rodriguez Gomez de Celis, wrote on Twitter.

"My condolences to the family. RIP," he added.

A hearse arrived at the site shortly after the news broke that Julen's body had been found.

There had been no sign of life from the boy but rescuers believed they knew where he was inside the illegal well.

The only evidence of the boy's presence were some strands of hair that matched his DNA and a bag of sweets that he had been holding when he fell into the well.

"All of Spain feels the infinite sadness of Julen's family. We have followed closely every step to reach him," Prime Minister Pedro Sanchez wrote on Twitter.

"We will always appreciate the tireless effort of those who searched for him during all these days."

Rescuers were not able to get to Julen via the well he fell down because it was blocked by a layer of earth, sand and stones believed to have been dislodged when he tumbled into the shaft.

They decided to dig a vertical shaft parallel to the well, 60 metres deep, which was finished late on Monday.

The idea was to secure the shaft with tubes then take elite miners down in a specially made cage to start digging a horizontal tunnel to the site where they believe the child was.

But the tubes designed to secure the shaft did not fit, so they had to widen it, which delayed the operation still further.

Julen's great-aunt Elena told private television Telecinco on Friday that "sometimes I fall apart because many days have passed and my boy is in a well, and we don't know if he is alive or dead. I believe he is alive."

Julen's parents lost another child, Oliver, aged three, in 2017. The child had cardiac problems.

The well was unmarked at the time of the accident and regional authorities in Andalusia said the necessary permission had not been sought before it was dug.