Strictly speaking, it can't be done (Score 1)

Bottom line, if you EVER had access to read either an electronic or paper document, you can NEVER conclusively prove that you didn't somehow gain a copy and do Whatever(TM) with said copy. Unless there was a human watching you during every moment of the access, or maybe you were videotaped during every moment of access.

You can implement systems to track who had access to a document. The more comprehensive these systems, the less likely it is that you'll be suspected of mistreating the document or information within. Such tracking increases accountability, though it's next to impossible to 100% assure that every person who accessed the data never did any unapproved thing with it.

If you don't want to do the aforementioned rights management services, then you can set file-level permissions to limit the number of people with access. If that's not enough, you can implement filesystem auditing, to log each access to the file. That narrows the suspect list even further, from those who CAN access the file to those who DID access the file. Both of these depend on a tight system of account administration controls, and the latter also depends on a trusted secure storage repository for the logs. Naturally the integrity of any or all of these systems can also be questioned.

Suddenly one gains appreciation for a system of justice which places the burden of proof on the accuser, eh? The only way to evade suspicion is to make sure you never had access to the thing you might be suspected of behaving badly with.