I will say with 100% certainty that ALL the Middle East countries bring into ALL EU countries whatever weaponry they wish, after bribing the import agencies. Been there & seen it first hand..
Then may I humbly suggest you take your evidence to the relevant authorities so that they can pursue possible prosecutions. Or are you that paranoid that you believe every official in the Home Office / Police Service / HMRC etc is corrupt and under the pay of Iran / Saudi / Russia / Insert Random Country of your choice.
Alternatively, sell your story to the papers - they like nothing more than a bit of Johnny Foreigner bashing, particularly if it includes corrupt civil servants.
But just watch out for the thick set gentlemen wearing an ill fitting, and lumpy, suit and dark glasses if you do either of these. Don't say you haven't been warned.