Kate McCann: 'Madeleine cried 18 hours a day'

Kate McCann has told of how Madeleine cried for 18 hours a day as a baby and demanded constant attention when her twin brother and sister were born.

In an interview with a Portuguese magazine, the 39-year-old GP is reported to have discussed her daughter suffering from colic and how, at 20 months old, she reacted to the birth of twins Sean and Amelie.

Mrs McCann's intention seems to have been to illustrate how she and Madeleine bonded so closely during those early years, when mother and daughter were rarely separated.

But her interview was seized on by detectives as valuable evidence in the profile they are building of her.

Officers are seeking medical records to build up a case that she was incapable of controlling four-year-old Madeleine - and that the strain could have provoked her into violence while on holiday in Praia da Luz.

The question of Mrs McCann's relationship with her children first arose last week after the Portuguese press published details alleged to have come from a diary she kept in the Algarve.

The diary extracts purported to demonstrate that she admitted she struggled to cope with her children, and had difficulties with Madeleine because she sapped her strength and emotions.

Mrs McCann's interview with Flash! magazine was conducted before she and her husband Gerry were named as suspects in the case and before the diary details were published.

In it, she spoke openly about her experiences in being a mother to Madeleine, candidly admitting that the first six months with her were "very difficult".

She explained that Madeleine frequently suffered from colic as a baby and, as a toddler, demanded a lot of attention after the birth of the twins.

"She cried practically for 18 hours a day," she said. "I had to carry her around permanently."

This period explained "the strong bond between mother and daughter", she said.

Although the arrival of the twins shook up Madeleine's life, she accepted them very well.

Mrs McCann is quoted as saying: "She managed to deal perfectly with this new reality, although she herself at the time was still a baby."

Her interview emerged as the police case against the couple appeared to be crumbling because of doubts over the reliability of any forensic evidence.

Sources told the Daily Mail that officers may even research information on Munchausen's syndrome by proxy - the condition can compel parents and other adults to harm children.

Madeleine (left) with twins Sean and Amelie

It has become a routine line of inquiry in child murder investigations since the case of Beverley Allitt, the hospital nurse who killed four children in 1991.

Allitt was convicted in 1993 on 13 charges of murder and causing grievous bodily harm.

Those suffering from the condition often have a high knowledge of medical practice.

In the context of this case however, the suggestion was being seen as another attempt to blacken the McCann name and put the couple under pressure.

In the interview, Mrs McCann insisted that she and her husband were "truly responsible parents" and had committed no crime.

Speaking of the night Madeleine disappeared, she said: "I was sure immediately that she didn't walk out of that room.

"I never doubted that she had been taken by someone.

"I went through a phase of guilt for not knowing what happened to her. I blamed myself for thinking that the place was safe.

"But the certainty that we are truly responsible parents has helped me carry on.

"I know that what happened is not due to the fact of us leaving the children asleep. I know it happened under other circumstances."

Asked about whether the decision to leave them meant she and her husband were responsible for their daughter's disappearance, she said: "It cannot be considered a crime.

"Someone committed one, but not us."