Madeleine McCann's mother says she and her husband will 'never give up'

Left: Maddie at age 3 in 2007. Right: An age-enhanced photo of how Maddie might look at age 6. Photos / Supplied

Kate McCann believes her daughter Madeleine's kidnapper did not take her "a million miles" from the Portuguese resort from where she was snatched.

Madeleine McCann was just three when she disappeared from the British family's holiday apartment in in May 2007.

Kate McCann vowed she and her husband Gerry would "never give up" hope of finding their daughter.

The 47-year-old, who is an ambassador for charity Missing People, said her research had led her to believe abducted children were not usually taken far from the scene.

"That's where she last was and I don't think she's been taken a million miles from there.

"I've always said Praia da Luz is the place where I feel closest to her," she told the Sun.

"The urge to look for Madeleine absolutely hasn't changed at all. You hear all the time about people who have been missing for years being found. There have been so many cases like that.

"We will never give up. You couldn't settle if you thought about giving up. I want an end, an answer. Whatever that it is."

She said that Child Rescue Alerts, a scheme of early warning messages she helped launch, could have "mobilised" people at the time of Madeleine's disappearance.

Since 2011, UK police have been helping in the search for clues as to what happened to the youngster with officers visiting the holiday resort in 2014.

The Home Office said in June that the investigation had cost £10 million (A$20.39 million), with a further £2 million budgeted for the year ahead.

-AAP