There are a multitude of agencies dealing with Madeleine's case & they have access to data & areas inaccessible to the parents. To date there is no proof she is dead - quite the opposite imo.
Are you aware there is also a reward currently being offered for information which will not be shared with the police?
http://www.anonymousreward.co.uk/madeleine-mccann/
"How to Claim in the Madeleine McCann case
How to claim your prize Anonymous Prize
1. Call PLYMOUTH (UK) 0044 1752 638 416
Call Plymouth (UK) 0044 1752 638416
2. Leave your information in Portuguese or English on our automatic recording service. You will not need to speak to us. Take care to RECORD your information very clearly.
Leave your information in our automatic recording services. You will not need to talk to us. Be sure to record the information clearly.
3. At the end of your information, create YOUR OWN PASSWORD. This can be whatever you wish. DO NOT disclose your password to anyone.
At the end of the information, create your own password. Choose any word and do not reveal it to anyone .
4. Call the number again in exactly 14 days. You will be asked for five digits from your password. If your information has proved to be credible, you will be informed where to collect your cash reward from. This will be in Portugal.
Call the number again in exactly 14 days. You will be asked for 5 digits of your password . If the information is correct you will be informed where you can raise your money in the UK.
Thank you. Your help with this case is very much appreciated.
Thank you"
Someone needs to call that number and see who is at the other end.