An amount of a lakh outstanding from a customer is disputed by the customer.How can this be disclosed in the accounts?

I have a question. Is the whole amount or part of the amount is disputed. The amount that cannot be recovered has to be treated as a bad debt. Even if the customer is not disputing the whole amount a reserve has to be kept  for bad debt depending on previous experiance.

Amount disputed is a contingent liability which has to be disclosed as a footnote in the Financial statements