Corporate Investigations After a Portfolio-Company Acquisition

When the Deal Closes, the Questions Change

Pre-deal diligence answers one question: should we buy this company, and on what terms? Everything after closing answers a different one: what is actually happening inside a company we now own? The two use some of the same methods, and they are not the same job.

Access is the first difference. Before closing, the buyer sees what the seller puts in the data room. After closing, the company's own records, systems and people are available to the company, subject to its policies and the law. Questions that diligence could only flag can now be tested against the ledger, the email server and the vendor file.

Authority is the second. Someone has to decide who the investigator works for, who receives the findings and who acts on them. In a portfolio company that can be the sponsor's deal team, the portfolio company's board, its management or outside counsel, and the answer matters more than it first appears.

This article is written from the investigator's side. It is general information, not legal advice. Federal law and policy discussed here were checked as of November 8, 2026.

Why the First Year After Closing Matters

Federal enforcement policy puts a clock on part of this work. The Justice Manual's provision on voluntary self-disclosure in mergers and acquisitions (section 9-28.900) applies a presumption in favor of declining prosecution of an acquirer that discloses misconduct at the acquired company within 180 days of closing, fully cooperates, and remediates within one year of closing.

Those periods apply "generally". Prosecutors may extend them where they have a reasonable basis, the acquisition must serve a bona fide business purpose, and other conditions apply. The Justice Department's corporate enforcement policy of March 10, 2026 still points to this provision for misconduct uncovered in pre- or post-acquisition due diligence.

Whether to disclose anything is a decision for counsel and the company. The investigator's part is earlier and narrower: finding out, inside that period, what actually happened and what the records show.

The Justice Department's Evaluation of Corporate Compliance Programs also looks at acquisitions. It expects comprehensive due diligence of acquisition targets and a process for timely and orderly integration of the acquired business into the acquirer's compliance structures and internal controls, and it notes that flawed or incomplete post-acquisition due diligence and integration can allow misconduct to continue. A sponsor will want to be able to show that the post-close work was done and documented. How Fortaris works with sponsors is set out on its private equity page.

What Corporate Investigation Services for Portfolio Companies Cover

Six post-deal situations are worth knowing in advance. Each starts with a specific question, and each has a point where the investigator hands the answer to counsel or the board.

1. Numbers that do not reconcile. Working capital comes in below the estimate, revenue does not convert to cash, or inventory counts disagree with the books. An accounting question goes to the accountants. The investigator's question is whether someone made the numbers wrong on purpose, how, and who knew. Fraud examination works from the transactions to the people, and the first thirty days of a corporate fraud investigation set out the order of work.

2. A tip about management. A hotline call, an anonymous letter or a departing employee's exit interview alleges something about a senior manager. Tips matter: in the Association of Certified Fraud Examiners' Occupational Fraud 2026: A Report to the Nations, 43% of the frauds studied were detected after a tip was reported. Each allegation is scoped on its own facts before anyone is interviewed.

3. Vendors or customers tied to insiders. A supplier shares an address, a phone line or an officer with a manager or a family member. Business registry filings, property records and court dockets can map who stands behind an entity, and the method is the same as checking a counterparty before you sign a contract. Whether the relationship was disclosed, and whether it cost the company money, are separate findings.

4. A seller or former manager who may be competing. The purchase agreement has a non-compete or non-solicit, and customers start leaving for a new business. Public filings can show who formed it and when. What was taken, if anything, is a question for preserved company records and counsel, and evidence preservation comes before any conversation with the person concerned.

5. Compliance exposure the diligence did not reach. A distributor abroad, a government customer or a sanctioned-country shipment appears in records the data room did not hold. Cross-border questions need records from several systems read together, which is the work of an international due diligence practice. The general 180-day period above makes speed matter here.

6. A new appointment or a board change. The sponsor replaces a CEO or adds an operating partner to the board. The public record can show whether a career matches its description. If the review informs an employment decision, federal consumer-reporting rules may apply, as discussed below, and that is settled with counsel before the work starts.

Who Should Direct the Work

Start with who the client is. If the person under suspicion is in management, management should not be the one engaging the investigator. The portfolio company's board, a committee of it, or the sponsor through counsel is the alternative, and the choice should be written into the engagement letter before work begins.

Counsel's role is more than formal. In Upjohn Co. v. United States, the Supreme Court held that attorney-client privilege protected communications between company counsel and employees made at the direction of corporate superiors to secure legal advice. Federal Rule 26(b)(3) separately protects certain documents prepared in anticipation of litigation. Whether a given investigation is privileged depends on how it is set up and run, so counsel should decide that at the start, not after the first report.

Lawful Sources and Stated Limits

After closing, the company's own records are the starting point: the ledger, bank statements in the company's name, email and messaging on company systems, expense data, vendor master files and access logs. Company policies on devices and systems, and the law where employees work, decide how they may be collected and reviewed. Public records come next: court dockets, business filings, property and lien records, and financing statements.

Some records belong to other people. A former owner's personal bank records, or a vendor's, come only through legal authority, such as a subpoena under Federal Rule 45 once litigation is under way. The shortcut is off the table: 15 U.S.C. § 6821 prohibits obtaining a financial institution's customer information through false, fictitious or fraudulent statements or documents, subject to its exceptions. Fortaris does not pretext, and its investigative services are scoped to lawful sources.

Purpose can change the rules. Under the Fair Credit Reporting Act, a report from an outside firm that is used to evaluate someone for employment, promotion, reassignment or retention can be a consumer report, and the employer then needs a standalone written disclosure and the person's written authorization first. Some investigations of suspected workplace misconduct are excluded, under conditions. Which side of that line an engagement falls on is a question for counsel at scoping.

What the Sponsor Should Receive

A sponsor reads a report differently from a court, and the report should be built for whoever will act on it. Three habits make it usable. Each finding names its source document and date. Confirmed facts are kept apart from inferences. Open questions are stated rather than smoothed over.

Agree in advance who receives interim findings, in what form and through whom. If a claim under the purchase agreement or a representations and warranties policy is possible, ask counsel early about its notice terms, because gathering evidence takes time. The same discipline applies before a deal, and the private equity due diligence playbook covers that side.

What the Investigator Does Not Decide

The investigator documents evidence. Counsel advises on legal exposure and on any disclosure to authorities. The board decides on employment action, claims against the seller and changes to management. A finding is not a determination of guilt, and it does not settle a dispute under the purchase agreement.

Conflicts are checked before work starts: any connection to the sponsor, the seller, the portfolio company or the people involved is disclosed. And the findings go in the file whichever way they cut, including when they clear the person who was suspected. Vetting the next management team is a separate piece of work, covered in vetting management before the close.