The investigation into the disappearance of Madeleine McCann is like no other I have seen before.

I have followed this case from the beginning. I visited the village of Praia da Luz within hours of Madeleine’s disappearance and have returned on numerous occasions to examine what happened on May 3 last year.

I believe that Madeleine was abducted outside her family’s apartment by an opportunistic paedophile with local connections. And I would be very surprised if this person has not been back to the area or still frequents it.

On the evening she disappeared I believe Madeleine woke up and cried for a short time while her parents were dining at a nearby tapas bar at the Ocean Club resort. When she realised that her parents were not there she climbed out of bed and walked around the apartment. She found the back patio door partly open so she walked out, went down the small flight of steps, through the metal gate and turned right down towards the entrance to the tapas bar. It was at this point that she was abducted. Interestingly, police dogs first tracked a scent down this exact route. It is a vital clue that has been largely ignored. Unfortunately, although this area is in range of a CCTV camera at the nearby super-market, it was not working that night.

Statistically the abduction of a child is very rare. On average it happens to six children a year in Britain. However, if we look at the abduction and murder of Sarah Payne in July 2000 we can see that she was snatched by a passing stranger while her brothers were just steps behind.

Madeleine became the victim of an opportunist and predatory paedophile. The abductor either lives in or had contact with Praia da Luz. This is not the sort of resort you just happen upon. For the past 12 months the Portuguese police have pursued only two lines of inquiry: that Gerry and Kate McCann were involved or that their daughter was abducted by a stranger. They have focused steadfastly on the first line. It is quite correct for the police to consider the parents as suspects because most murdered children are killed by a relative or someone they know. But the police do not seem to have any real evidence against Mr and Mrs McCann and they have vehemently denied any involvement.

Mr and Mrs McCann believe their daughter was abducted and trafficked abroad but Madeleine does not fit the profile. Girls are trafficked into the sex trade as prostitutes or for domestic slavery, both with financial gain to the seller and purchaser. Who was to gain from her trafficking?

The so-called sightings in other countries, although genuinely intended, are a distraction and prove to be of little value after the initial two weeks. After all who is going to openly walk out with the most wanted child in the world? For months it was genuinely assumed the abductor had entered the apartment and taken Madeleine from her bed. But I do not believe that a paedophile was watching the apartment or that an offender entered the apartment.

This would be too high risk as the offender would not know that someone was not inside. Britain has not seen a single case of a predatory paedophile entering premises and abducting a child where the occupants of the house are unknown to the offender.

The problem with the police investigation was that it was crucially flawed from the very start. It was the worst-preserved crime scene I have seen.

The investigation is now all but closed. The police have insufficient evidence to charge Mr and Mrs McCann and when their arguido status is lifted the couple could return to Portugal without fear of arrest or prosecution.

They could then properly coordinate an investigation to find out what really did happen to Madeleine.

Mark Williams-Thomas is a former detective and authority on paedophile crimes

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