Last updated at 17:38 22 July 2007

The parents of missing Madeleine McCann have been the victims of a Portuguese smear campaign over their decision to leave their three children alone in their holiday apartment.

According to reports, a whispering campaign has begun in Portugal accusing Gerry and Kate McCann of neglect after they left the toddler and her twin brother and sister in the apartment at the resort at Praia da Luz on May 3.

The campaign is being fuelled by activity on internet chatrooms and in the Portuguese press, the Sunday Express claims.

The couple had been dining at a tapas restaurant with friends on the night Madeleine disappeared and were taking turns to leave the table to check on their children.

The Sunday Express said the couple have been "outraged" by the complaints and had taken legal advice.

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The McCanns' spokeswoman, Justine McGuinness, said: "If they could turn back time there are things that they might have done differently, with the benefit of hindsight.

"But it is impossible to say whether, had there been an adult in the apartment at the time of the abduction, it would have stopped a predator."

Madeleine's father is due to arrive in America today for a four-day visit to learn about the work of specialist agencies who help prevent child abductions and sexual abuse, as well as legislation that has strengthened U.S. laws against child sex offenders.

"After visiting the Child Exploitation and Online Protection Centre in London, I wanted to understand better the work that is being carried out across the world to reduce child abductions," he said.

"I am going to the USA to meet experts at both the National and International Centres for Missing and Exploited Children.

"We want to work closely with the police and child welfare agencies in maintaining the profile of Madeleine's and other children's disappearance."

The latest exercise in keeping four-year-old Madeleine's face in hearts and minds is related to the latest Harry Potter book. Her poster is being displayed at booksellers in more than 200 countries alongside the final instalment of the boy wizard's adventures, Harry Potter And The Deathly Hallows.

However, thousands of yellow ribbons tied to a war memorial in Madeleine's home village as a symbol of hope are going to be removed.

Her great-uncle Brian Kennedy said the railings around the memorial in Rothley, Leicestershire, would be stripped of ribbons by August 1.

He added: "We are not giving up the search but we think the time has come to move on a bit."