Financial Fraud and Condo Association Board Responsibilities

I took over as treasurer for our condo association board in December. After review of the books, I found a suspicious account for Pool Chemicals. I cannot find the company anywhere, phone #'s don't work, there is no such box number, there was a $3000 cash deposit made back into the condo association check book and we were told the company went out of business and returned the money.

Only after a request for an audit was made, checks were cashed by a card services and they were made out to an incomplete name similar to the one used in the check register, not the same name, but never in the full name of the pool company. The books have been removed from present management company. What are the legal responsibilities for the condo association board of directors to follow from this point forward. We are talking close to $100,000.