Madeleine: Disappearance of Spanish girl 'brings awful emotions back' as Kate and Gerry pray for heartbroken parents

Mr McCann, 39, told how the suspected abduction of Mari Luz Cortes in Huelva, on the Spanish border with Portugal, had forced him and his wife to relive the agony of Madeleine's disappearance in May.

The couple's private detectives have begun investigating Mari's disappearance, only 120 miles from Praia da Luz, and promised to pass any information they gather to Spanish police and the Cortes family.

Scroll down for more...

Investigators are probing if the two girls' disappearances could be linked, or even if they could both have been snatched on the orders of a paedophile network, and have spoken to Mari's anguished parents.

Mr McCann said: "Hearing of the probable abduction of Mari Luz Cortes has brought many awful emotions flooding back.

"We hope and pray that Mari is quickly found and returned safely to her family."

Mari disappeared just before 5pm on Sunday after walking from her home in the rundown Torrejon estate in Huelva to a nearby kiosk to buy a packet of crisps.

Scroll down for more...

A massive police search using helicopters and sniffer dogs failed to find any trace of her and her family fear she was abducted.

They have admitted her disappearance could be linked to Madeleine's but said it was "too painful" for them to think about what could have happened to the girls.

Police yesterday scoured the coastline near the city, in the south west corner of Spain, and boats searched the sea and marshland amid fears her body could have been dumped.

Portuguese police have also carried out searches on their side of the border, and have not ruled out a possible link between the two girls' disappearances.

Mari's family held a huge rally near their home yesterday, where more than 2,000 people marched through the streets demanding her safe return.

Scroll down for more...

They held pictures of Mari and banners saying "Mari Luz we love you, come back quickly" and "We will find you, justice will be done".

The little girl's parents walked with the marchers but her mother Irena collapsed with grief a short distance from their apartment and had to be taken home by relatives.

Mari's father Juan, 34, appealed directly to his daughter's suspected abductor, saying: "We are heartbroken. All we ask is that you return our daughter."

He added: "It's vital that anyone who knows anything about the first hours of our girl's disappearance, which are the most important, that they tell the police so they can direct the search better."

A friend of the family addressed the crowd on a megaphone, shouting: "Where is God? Where is God?"

Parents walked with their children, and said many youngsters in the area were now afraid to go outside alone after Mari's disappearance.

Her headmaster Baldomelro Rodriguez said: "Everyone now feels as if we have been kidnapped like Mari Luz, and everyone is now united in the same family.

"We decided to march because the disappearance of a child is painful and tragic and a blow to society."

Her tearful teacher Maria del Carmen Feria Limon said: "Mari Luz is a wonderful child with great joy and liveliness."

Police are continuing to check a witness's claims that they saw Mari crying on a bus at 8pm on Sunday, with a gypsy woman who was shouting at her to keep quiet.

Her mother said the description matched the clothes her daughter was wearing when she vanished, and said she believed it could be Mari.

There have been several sightings of Madeleine with an older woman in northern Morocco, and detectives from the Spanish detective agency Metodo 3 believe the Berber woman is a "carer", keeping the four-year-old alive in the Rif Mountains on the orders of a paedophile gang.

Meanwhile Portuguese police have written to their counterparts in Britain, asking them to re-interview the McCanns and their friends.

They insist Madeleine died on the night of May 3, possibly at the hands of her parents. The McCanns have denied any involvement in her disappearance.