...as forgery experts admit they can't spot fakes
Germany has been inundated with 500,000 refugees already this year
But authorities say they are 'powerless' to stop tens of thousands of migrants using fake Syrian documents to claim asylum
A huge number of applications supported by passports appear to be false, a police forensic expert revealed
Economic migrants from north Africa claim to be from war-torn Syrians
Expert told MailOnline 'I know their documents are false but I can't prove it'