From my experience working in a bank, high commissions or embassies send inquiries to the bank to verify the authenticity of what the applicant submitted (statement of account or fixed deposit certificate and covering letter). What they're basically requesting is for the bank to confirm that those documents emanated from their office and that they're valid. What the bank confirms in reply is that the documents emanated from them and they're valid as at the date issued. The bank will not normally say "this is the current balance on the account" or something like that.
Having said all that, I still think you should leave the funds jeje-ly o. This is Nigeria, you can never tell, AVO may request specifically that you generate another statement covering a 6month to 1 year period. And if the money no show say e don dey sit there since...... hmmmm, I no know o