Police have announced they are looking for one man who they believe might hold the key to unraveling everything. This is a man who they have previously interviewed, and who used to work at the resort. Source: http://www.mirror.co.uk/news/uk-news/madeleine-mccann-cops-hunt-worker-10013618

Another, earlier article from August 2016 indicates who that man might be.

The police previously interviewed him as a suspect, and he used to work at the resort.

Jose Carlos da Silva, 30. He used to drive guests to their apartments at the Ocean Club resort in Praia da Luz. The police actually listed two other names who this man was in contact with. Ricardo Rodrigues, 24, and Paulo Ribeiro, 53. Source: http://www.mirror.co.uk/news/uk-news/madeleine-mccann-cops-hunt-worker-10013618

Perhaps these were the scouters who did the dirty work for more powerful people above them.

Now, if these names could be cross-checked and connected to certain other names that might be involved....