Where can we view the comments and attachments entered during supplier approval?

Summary:

Where can we view the comments and attachments entered during supplier approval?

Content (required):

We have set up internal supplier registration approvals to route to 3 approval groups in sequence. As each group approves, they enter comments, and sometimes attach files, that the next approver uses to determine what to evaluate before they approve. Once the supplier has been approved, they need to be able to access these comments and attachments for auditing.

If I go into the BPM worklist and find the completed task, I can see the comments and attachments there, but I believe that gets purged at some point, right?