For eight years now Gerry and Kate McCann have fought tirelessly to find Maddie, who disappeared from her family's holiday in Portugal's Praia da Luz in May 2007
Thirty-one police and support staff are still trying to find Maddie but in the four years since the beginning of the investigation ordered by PM David Cameron, no arrests have been made.
Although Maddie's is one of the most high-profile cases, each year 140,000 children go missing - and one per cent of cses remain unsolved after a year.
Here we ask Kerry Needham, whose son Ben disappeared 20 years in Kos, Greece, for her views
In July 1991 toddler Ben Needham vanished outside a farmhouse his grandparents were renovating on the Greek island of Kos, while his mum Kerry was at work.
His family combed the countryside for the 20-month-old but, tragically, he was never found.
KERRY NEEDHAM REVEALS ON ITV'S THIS MORNING: "I KNOW THAT BEN IS STILL ALIVE"
Despite Kerry pleading with the Government for more help, less than £800,000 has been spent so far – just a fraction of the £11m used in the search for missing Maddie.
Now, 24 years on, Kerry Needham, 43, says she’ll never give up looking for Ben and thinks it’s unfair the McCann’s have received so much money, compared to other missing children investigations.
She adds: “My heart goes out to the McCann’s, having a child go missing is an indescribable pain. There is no closure and you miss them everyday.
“But I don’t understand why the McCann’s have received so much - £11m is unprecedented.
"It seems unfair when other missing children aren’t getting as much attention and money.
I’ve come up against so much resistance from the Home Office when I’ve asked for help finding Ben.
“I understand that Kate and Gerry will never want to give up searching for Maddie but there have been no arrests and there don't seem to be any leads.
"It seems the police have done all they can - which isn't the case with Ben.
"There is still hope for Ben. Even this year, police have uncovered information that has led to new lines of enquiry."
At the time of Ben's disappearance, Kerry says she received no help from the Government.
She recalls: “No one from the British Embassy came to meet me and no British police were flown to Kos.
"It wasn’t until 2011 that British police finally sent officers out. The South Yorkshire police did help when we returned home, but we had no funding from the Government. If there was a lead I’d fly out myself with money I’d raised through campaigning.
“When Maddie went missing, British police were flown out within two days.
“The government simply wouldn’t be able to afford to spend £11m in every missing child case, there should be a certain amount attributed to each case depending on how many leads there are.
“We’ve received less than £800,000 from the government, and most of that was given to us this February after a lengthy appeal to investigate leads previously ignored by Greek Police.
"We’ve done most of the work ourselves with the help of the public.
"Of course I want Madeleine to be found safe and well, but why do the “McCanns get more help than the rest of the families with missing children? It’s unfair.”