US law protects certain information, not otherwise protected under the attorney–client privilege, from disclosure when it qualifies for work product protection.5 This doctrine, known as the work product doctrine, protects both tangible and intangible work product6 and encompasses documents prepared in anticipation of litigation or for trial. Actual litigation is not necessary but there needs to be a threat of litigation. In some jurisdictions, a threat of litigation is present when litigation is imminent. In others, there need only be a credible probability that litigation will ensue. In the context of government investigations, courts generally find that litigation is imminent or that there is a credible probability that litigation will ensue once the investigation has begun.
There are two types of work product: ordinary work product and opinion work product.
Ordinary work product
Ordinary work product consists of factual material gathered by the attorney, and can include information obtained from the client and third parties. Ordinary work product is subject to a qualified privilege. It can lose its protection from disclosure if opposing counsel can show a substantial need for the workproduct material and a hardship in obtaining the needed material by other less intrusive means.
Opinion work product
Opinion work product is work that includes the attorney’s mental impressions, conclusions, opinions, or legal theories and it is considered nearly sacrosanct and afforded strong protection against disclosure.
Notes or memoranda of interviews of company personnel conducted by in-house or external counsel may be protected by both the attorney-client privilege and attorney work product doctrine. To ensure strong work product protection, the notes should include the mental impressions of the lawyer where appropriate and should not be disclosed. The underlying facts may not be privileged and could be sought by third parties, including regulators, if relevant to a legal proceeding or government investigation.