Very high risk, in my opinion, and good luck getting hold of your funds after the 5 year period, which if the company is still in existence, is highly unlikely to be a simple procedure as any amount of financial delaying/avoidance strategies could be lawfully employed.
(Not that I am suggesting this will be the case as I am sure that all persons involved in the management/operation of this scheme are upstanding people without a deceitful thought in their heads.)
But, be prepared to lose your entire investment without the normal safety-net avenues of recourse to go to and a well repeated maxim is that ‘If it sounds too good to be true then it is invariably exactly that’, so I can only suggest that you exercise the most extreme caution when considering this and similar investment ‘opportunities’.
Please note, the content of my reply is my personal opinion only and my comments are not in any way to be construed as offering financial advice.