Maintaining Confidentiality in Internal Corporate Investigations

Lesley Brovner & Mark Peters
April 9, 2026

Confidentiality is one of the most important and most challenging aspects of any internal corporate investigation. Investigations often uncover sensitive information involving potential misconduct, legal exposure, trade secrets, private employee data, and strategic business issues. As a result, companies must decide early whether they intend to protect investigative materials from disclosure, whether disclosure may ultimately be necessary, and what legal protections may apply.

Attorney-client privilege and the work product doctrine are the primary tools used to preserve confidentiality during an internal investigation. But they are not absolute. Companies must also consider waiver risks, confidentiality agreements, government cooperation expectations, and shareholder discovery efforts when deciding how to handle investigative materials.

Why Confidentiality Matters in Internal Investigations

Internal investigations generate a wide range of sensitive materials, including:

  • interview notes and memoranda
  • questionnaire responses
  • legal research and strategy memoranda
  • drafts of reports
  • final investigative reports
  • materials prepared by accountants or other experts retained by counsel

Protecting these materials can be essential for several reasons. Confidentiality helps preserve the integrity of the investigation, encourages witness cooperation, protects privacy interests, and reduces the risk of unnecessary reputational or commercial harm.

Investigations may also involve confidential customer information, supplier data, trade secrets, or highly sensitive internal financial records. Public disclosure of that information can create separate legal and business risks beyond the original misconduct under review.

When a Company May Decide Not to Insist on Confidentiality

Although companies often have strong reasons to maintain confidentiality, there are times when disclosure may be strategically beneficial or legally necessary.

A company may decide to disclose investigative findings when:

  • criminal wrongdoing may require self-reporting
  • regulators expect cooperation
  • securities laws require corrective public disclosures
  • the company wants to restore investor, customer, or employee confidence
  • law enforcement seeks evidence as part of a broader inquiry

In these situations, disclosure may help the company obtain cooperation credit, reduce enforcement risk, or demonstrate that it responded appropriately to serious allegations.

Even when a company is unsure whether it will eventually disclose the results, it is usually best to begin the investigation as though confidentiality will be preserved. That approach preserves flexibility later.

Attorney-Client Privilege in Internal Investigations

Attorney-client privilege is a central protection in internal investigations. It applies to confidential communications between counsel and the client made for the purpose of obtaining or providing legal advice.

In the corporate context, that protection can extend to communications between company employees and company counsel during an investigation, provided the communications are made so counsel can render legal advice to the corporation.

For the privilege to apply, companies should make sure that:

  • one purpose of the investigation is to obtain legal advice
  • counsel’s legal advisory role is clearly documented
  • employees understand counsel represents the company, not them individually
  • communications are intended to remain confidential and are treated that way

Courts generally will not allow a company to label ordinary business records as privileged merely because they were later sent to counsel. Raw corporate records typically remain discoverable unless another protection applies.

Work Product Protection for Investigation Materials

The work product doctrine is broader than attorney-client privilege and protects materials prepared in anticipation of litigation.

This protection generally falls into two categories:

Non-opinion work product

This includes factual materials such as witness statements, timelines, and factual reports. It receives qualified protection and may be discoverable if an opposing party shows substantial need and cannot obtain the equivalent without undue hardship.

Opinion work product

This includes counsel’s mental impressions, legal theories, conclusions, and strategy. It receives significantly stronger protection and, in many courts, is close to absolute.

To strengthen work product protection, companies should create a record showing why litigation was anticipated. That record can appear in board resolutions, engagement letters, meeting minutes, and investigation reports.

Common Interest and Joint Defense Protections

In some investigations, multiple parties may share a common legal interest and wish to exchange information without waiving privilege. This is often referred to as the common interest or joint defense doctrine.

This protection can apply when parties:

  • share a common legal interest
  • are pursuing a coordinated legal strategy
  • intend to keep shared information confidential

A written common interest agreement is the safest way to establish the arrangement, although some courts may recognize oral or implied agreements depending on the facts.

These agreements can be useful, but they also create risks. In some cases, they may complicate future adversity between the parties or create arguments about duties owed across the group.

The Limits of the Self-Evaluative Privilege

Some companies argue that internal investigation materials should be protected under a self-evaluative or self-critical analysis privilege. The theory is that companies should be encouraged to investigate themselves candidly without fear that the resulting analysis will be used against them.

This doctrine has not been widely accepted, and many courts reject it outright or apply it narrowly. Where recognized, it is usually qualified and can be overcome by a showing of need.

Because of its uncertain status, companies should not rely on this doctrine as their primary confidentiality protection. Attorney-client privilege and work product protection remain far more important.

Waiver Risks When Sharing Investigation Materials

One of the most significant confidentiality risks in internal investigations is waiver.

Disclosure of privileged or protected materials to a government agency, outside auditor, or third party may waive attorney-client privilege and, in some cases, work product protection. Most courts reject the idea of “selective waiver,” meaning that once a company voluntarily gives protected material to the government, it may not be able to withhold the same material from private litigants later.

Waiver issues become especially complicated when companies try to cooperate with regulators by providing oral summaries or “downloads” of witness interviews. Courts have sometimes found that those disclosures waive protection over the underlying notes and memoranda.

Because of this, companies must weigh the benefits of cooperation against the downstream risk of broader disclosure.

Using Confidentiality Agreements to Reduce Disclosure Risk

Before producing materials to regulators or third parties, counsel should try to negotiate confidentiality agreements that:

  • restrict further disclosure
  • preserve privilege and work product objections
  • disclaim any intent to waive protections
  • require notice if third parties later seek the materials

These agreements are not foolproof, but they may improve the company’s position and sometimes help block later public-records requests or third-party discovery efforts.

Similarly, in private litigation, companies should seek stipulated confidentiality orders or protective orders whenever investigative materials are produced.

The Crime-Fraud Exception

Privilege and work product protections do not apply if communications or materials were used to further a crime, fraud, or similar misconduct.

This exception can become an issue where investigative reports are alleged to omit key information or are used to conceal wrongdoing rather than address it. The best practical protection is a thorough, good-faith investigation and careful reporting that errs on the side of including material information where appropriate.

Confidentiality Challenges in Shareholder and Derivative Litigation

Shareholders and other private litigants may seek access to investigative materials in derivative suits or other fiduciary-duty and securities cases.

Courts sometimes treat these requests differently than requests from the government. In certain derivative cases, shareholders may be allowed to show good cause why privilege should not apply, especially where they argue they are acting in the corporation’s true interest.

If an investigation report is filed in open court to support dismissal of a derivative suit, privilege may be lost for the report and possibly some underlying materials. For that reason, companies should seek protective orders and confidentiality restrictions whenever possible.

How Peters Brovner Helps Protect Sensitive Investigation Materials

Confidentiality decisions made at the beginning of an internal investigation can shape regulatory exposure, litigation risk, and the company’s ability to control sensitive information later. Peters Brovner advises corporations, boards, and compliance leaders on structuring investigations to maximize privilege protections, manage waiver risk, and respond strategically to government and shareholder demands.

Our team helps clients preserve confidentiality where possible while navigating the practical realities of disclosure, cooperation, and litigation.

When sensitive information is uncovered during an internal investigation, the decisions made about confidentiality, privilege, and disclosure can have lasting consequences. Peters Brovner advises corporations, boards, and compliance leaders on how to protect investigative materials, manage waiver risk, and respond strategically to regulators, shareholders, and other third parties. Contact Peters Brovner to discuss how we can help safeguard your investigation and position your organization for the next steps.