London - The Madeleine posters in Britain's pub windows may have faded but suddenly, one year on from her disappearance from a holiday apartment in Portugal, the pretty girl's smile is everywhere again.

"They didn't find Maddie yet, did they, Mummy?" is reported to be a frequently-asked question by British youngsters whose media acquaintance with the fair-haired toddler has turned Madeleine into something of a friend.

The disappearance of Madeleine McCann, eldest child of a doctor couple from Britain, from a holiday apartment in Praia da Luz, on the Algarve, on May 3 last year is the "biggest human interest story of the decade," Britain's publicity guru Max Clifford believes.

"As a PR exercise, in terms of awareness, there has never been anything like it," said Clifford. The Daily Telegraph called it the "most heavily reported missing person case in modern history."

The fate of Maddie, who turns five on May 12, has been the subject of an unprecedented publicity campaign initiated by her parents, Gerry and Kate, who are marking the anniversary with a fresh media offensive, prayers and appeals for help.

Commentators have suggested that it is the combination of an attractive holiday location, a pretty child and middle-class parents that has kept the interest in Madeleine alive and kept reporters on their toes for more than the usual few weeks.

"The parents are good-looking, articulate and Madeleine is a very pretty child," said Kate Morris, a psychologist attempting to explain the fascination.

The McCanns, aware of the criticism their high-profile campaign has aroused in some quarters, say they have no regrets about putting themselves in the public spotlight.

"We are not characters in a soap opera or fiction. This is about a real child and a real family who have been traumatised by this," Gerry said in a BBC interview to mark the anniversary.

It would be a "disservice" to Madeleine to give up their fight - and their belief that she is still alive, added Kate.

Missing People, one of Britain's leading charities involved in the search for lost children, said it "welcomed and applauded" the McCanns' attempt to "raise the profile of the wider problem of missing children."

But, in a statement marking the anniversary, the charity gave a reminder that thousands of families were affected by a similar fate.

"Everyday at Missing People is marked by at least one anniversary of a missing relative. The circumstances will be different but the pain is the same," chief executive Paul Tuohy said.

In Britain alone, 210,000 people would have been reported missing in the year since Madeleine disappeared.

The charity, which helps around 2,000 families a year and finds, on average, 10 missing people each week, said it hoped that the awareness raised by the McCann case would help people to understand that "missing" was a "social issue that can affect every one of us."

"We now need the public to share support for all missing people," said Tuohy in reference to the private donors' fund set up for Madeleine.

Like the McCanns, the charity has been campaigning for the Europe- wide introduction of an US-style quick response system - known in the US as Amber Alert - to help trace abducted children.

So far, only France has adopted a full alert system which involves immediate broadcasts on radio and television about missing children.

However, retracing the events since Madeleine vanished from her bed in a room she shared with her younger twin siblings Amelie and Sean, while the parents were eating in a nearby Tapas bar, it appears that initial mistakes in an allegedly "bungled" investigation have led to stalemate.

While Kate and Gerry McCann, as well as expatriate Briton Robert Murat, remain official suspects - or arguidos - under the Portuguese legal system, investigators have indicated that the file could soon be closed.

"I think it's safe to say we're getting very little information. We haven't had any communication in terms of what's been done in the investigation. We would like to know what's being done to find Madeleine," Gerry McCann said this week.

In Portugal, investigators have conceded that detectives could have been "hasty" in declaring the McCann's suspects last September. But, otherwise, they have remained tight-lipped.

"The police have gone down a blind alley and they don't know the way out," an unnamed senior Portuguese Justice official said in a BBC radio documentary on the case.

Meanwhile, the McCanns hope that secrecy laws relating to the case will be lifted later this month. (dpa)