Well, I have not been following all the twists of the Madeline McCann case in minute detail, certainly not from the start, but I think Moonraker is right in saying the police seem to have felt the parents were uncooperative - not offering tbe kind of assistance that people would most often give when they are living the shock that their child (or a parent) has disappeared. The business about that toy animal, for instance, which the police would have liked to see and examine at once: refused (I don't recall if it was before or after, that the police search dogs had spotted "smell of death" on this cuddle pet, but the McCanns were clearly not keen on handing it over to them for a brief spell)
These parents preferred, after the first two or three days, to grind their axes through the media, were followed by reporters everywhere they went, and held press conferences as if the police didn't exist (everyone knows it can be vital not to toss about facts of who did what or about the scene of the crime before you have someone charged in court - for one thing you want to be able to separate out the crackpots who turn up at the police's door in sensational cases like this, or write letters, saying I did it! by probing them about some things only the police, the real perpetrators and the injured family would know...) The local police force at Prada de Luz is obviously a small one, but they soon got assistance from police squads higher up.

TYWD, I plainly don't think the idea that the family were spied out by a bunch of paedophiles or other abductors is a credible one - why strike in this tourist town when you can no doubt get kids much safer in the countryside or just by importing them from Eastern Europe? Paedophiles don't much care about that it should be a fair English kid, but the media do. - Even car traffic seems to be rare which would make the crucial step of getting away from the place with a child who doesn't know you at all a very exposed and risky one. And if it was a standard kidnapping, why hasn't anyone turned up and demanded ransom money?

You may surmise that Mr. Ramsey or any John Blow abducted the girl, but the police have to be allowed to make a useful investigation, gather up technical traces and information and to single out, over time, who they think could be likely suspects - and try gaian if it proves aded end.

None of us seem to know just what is the legal import of "aguidos" but I think Moonraker could be right that it doesn't by default mean "prime suspects for being involved in the crime", but could also be a way of giving both police and the aguidos new powers of formal investigation/knowledge.