VOD,
I would fully expect an independent security force to be very unwelcome in light of the governmental officials "off the record" statements. Which is why I would let the force know that the threat level is accordingly high. If the cost for the force exceeds that of the "protection fees", then I would recommend to my employer that unless they have other reasons for staying, that they should walk away.
The inference I perceived is that unless I as the "individual in charge of financials", submitted to a bribe, then I might expect bad things to happen to my project staff. In my mind this was a direct threat made by this governmental official. Would throwing money his way actually help the situation or just add fuel to the fire? Would there be additional protection "fees" needed at a later date? Having no way to know, I choose to either prepare for a threat using known resources, or walk away. As a representative for my employer, I would consider either option professionally ethical. If I or another firm submitted to this "off the record" request, then I would consider it professionally unethical.
Personally I would regret having to walk away and be unable to help those in need. I would offer them what personal assistance I could in helping them make their own lives better. In this manner, I would not be acting on behalf of my employer.
Yes this answer separates the professional from the personal consideration of ethics. However, as an employee representing my employer, I have agreed to abide by their rules of conduct. On a personal level, I would as an individual try to do what I could to aid those in need.
Regards