I have been through this and can understand his perspective.

A few things to consider
-What quarter is it?
-What terms were laid out in your LLC operating agreement
-Did you have recipts, everoted from mint or financial tracking ( if not do this right away to protect yourself)
-Did you spend money on a consulting draw/ working capitol
-Did you completely bleed the funds?
-Is the investor reasonable with the deliverables

I would take this request seriously yet abide by audit agreements. It takes a tremendous amout of time to share these deliverables. Each investor is different. VC's are more seasoned so request professional processes. If you need some pointer, ring me and i can share how to get more time or how to proceed without your investor getting paranoid they will lose their money.