I'm currently watching the documentary but haven't finished it yet.
Just on the police investigations though from earlier comments, there have only been 3 British children go missing abroad. One is MM, the other is Ben Needham and the third is Katrice Lee. The Gov have funded the Ben Needham investigation in recent years, but it's not closed.
Katrice Lee investigation is the responsibility of the MoD police as she disappeared from an army base. This case isn't closed either.
And although £11m is a lot of money, it's a drop in the ocean compared to the c£14bn that policing spends in England and Wales each year. Giving the £11m to the 43 forces would have made no difference at all to any of the other investigations, particularly since the £11m has been spent over 6-7 years.
And the UK Police can't just rock up abroad. The Portuguese Police have primacy and we can't go in mob handed just because a Brit Cit is missing. The other country has to ask us for assistance.
The Portuguese Police also have the reputation of being a bit like Life on Mars. In that, they decide who's guilty and they then fit the evidence to their theory. I wouldn't believe anything they had to say - and the previous behaviour of the lead investigator suggests that he's not the one you'd want to rely on to solve the case.