As the above. Can someone shine some light into this ?

Security, bona fides, maybe to satisfy bureaucrats and reduce the need for customs to search for drugs, money weapons etc?

Or perhaps just as a substitute for a credit check which aren't much good for foreigners overseas. . .

Unusual, as the payment is made in advance, except duty and taxes.

Are you buying a ff company?

Nope im not Kurnell. I just need to export goods from time to time. And they need to see my bank statement for 6 month previous backtrack