Dry your eyes
I'm all in favour of contractors being able to charge 2 or 3 times what I get paid on a daily basis. I don't even begrudge them the Ltd company dodge that gives them a slight tax advantage given the lack of employee protections they get.
But as soon as I saw the words "offshore" and "interest free loan" my sympathy for anyone in this situation evaporated and I hope the taxman hits you like a ton of bricks
Contractors paid £500+ p/d are already heavily compensated for the lack of employee protections and job security. There is a reason my contractor friends are driving around in Porsche's and Mercs and I'm not.
They don't need an even greater tax break than they already get by running everything through a ltd company