When a forensic accountant becomes an expert witness
What changes when a forensic accountant's findings head for court: evidence that survives challenge, objectivity threats and a report for a judge.
By Achekam · · 5 min read · For Accountants & audit firms in South Africa, Nigeria, Kenya
Most forensic engagements end with a report to the client: what happened, who was involved and what it cost. Some do not end there. The client lays charges, sues a former director or defends a claim, and the accountant who did the work is asked to give evidence.
At that point, everything the accountant did is looked at by people whose job is to find weaknesses in it. The analysis must be sound, the evidence must be traceable, and the accountant's independence must be beyond question. Firms that take on forensic work in South Africa, Nigeria or Kenya should plan for that possibility from the first meeting, not when the subpoena arrives.
The forensic process can end in court
ACCA describes forensic accounting as the whole process of investigating a financial matter, including potentially acting as an expert witness if a fraud comes to trial. It explains that the purpose of an investigation into alleged fraud is to discover whether a fraud actually took place, identify those involved, quantify the client's loss, and present findings to the client and potentially to court.
ACCA also notes that forensic accountants may be asked to look at non-fraud matters, such as monetary disputes. Shareholder disagreements, business valuation disputes, insurance claims and damages calculations can all put an accountant in the witness box.
The difference between advising a client and giving expert evidence is the audience. A client wants to know what happened. A court wants an independent, reasoned opinion that it can test.
Evidence that survives challenge
ACCA warns that forensic investigators must keep a clear chain of custody over evidence, because inconclusive evidence or gaps in custody may lead to the evidence being challenged in court or becoming inadmissible.
For an expert witness, that warning has a personal edge. Opposing counsel will ask how each document was obtained, who handled it, whether it could have been altered, and whether the accountant looked at everything or only what supported the client's case. Practical habits that help:
- keep originals exactly as received, and work on copies;
- record every source, including documents asked for and not provided;
- keep the analysis reproducible, so another expert could follow it and reach the same arithmetic;
- record assumptions and their basis in plain words;
- keep notes of meetings and interviews made at the time.
Achekam's Document Centre gives each client a vault folder where staff upload files and folders, keep versions, tag, archive and restore with a reason, and search. Files sent for intake are filed as originals in an "Uploads for processing" folder. Kept that way, the file can show what was received and how it changed, which is the record an expert may be asked to produce. Keeping a chain of custody over evidence sets out the custody routine in more detail.
Advocacy and self-review threats
The IESBA Code's conceptual framework groups threats to the fundamental principles into self-interest, self-review, advocacy, familiarity and intimidation threats. The IESBA publishes the Code on its Code of Ethics page, which is where a firm should check the current wording.
ACCA explains that a forensic investigation requested by an audit client potentially exposes the investigating firm to self-review, advocacy and management threats to objectivity. Self-review arises because the firm may end up evaluating figures it audited. Advocacy arises because supporting a client's case in a dispute pulls against objectivity. Management threats arise if the firm drifts into making decisions that belong to the client. ACCA's article records that the IESBA's April 2021 revisions to the Code include a prohibition on audit firms providing a non-assurance service that might create a self-review threat to an audit client that is a public interest entity.
For an expert witness, advocacy deserves particular care. The accountant is instructed and paid by one side, but the opinion must be the accountant's own. If the evidence points against the client, the report must say so.
Writing for a court, not only for the client
A report intended for a client can assume shared context. A report that may go before a court cannot. Points to build in:
- State the instructions and the questions the expert was asked to answer.
- List every source relied on, and any that were requested but not received.
- Separate facts from opinions, and explain the reasoning that connects them.
- Show the calculations, with assumptions and alternatives where the evidence allows more than one view.
- Stay within expertise. Whether someone acted dishonestly is usually for the court; the accountant explains what the records show.
- Expect to be cross-examined on every sentence.
The procedural rules on expert evidence differ by court and country. The instructing attorneys or lawyers should explain what the relevant court expects, and the firm should follow that advice.
Working papers built for scrutiny
Achekam ships working-paper template packs written in its own words, including a pack for forensic work, for a firm to adopt and approve. The catalogue is marked unapproved platform content until the firm adopts it, and the firm should confirm the pack is available in its own workspace before planning around it. Once adopted, it gives the team a consistent structure for documenting procedures and findings, which helps when another party examines the file.
Accepting the assignment
Before agreeing to act as an expert, the engagement partner should be able to answer yes to each of these:
- Is the firm free of threats it cannot reduce to an acceptable level, particularly for audit clients?
- Does the team have the expertise the questions require?
- Can the firm obtain the evidence it needs, with custody intact?
- Are the instructions clear, in writing, and limited to matters within the firm's expertise?
- Does the client understand that the expert's opinion will be independent, even if unwelcome?
For how forensic work fits alongside a firm's other services, see internal audit and forensic assignments. Discuss these questions with the client at acceptance; it is much easier than raising them after the report is written.
General guidance only, not advice on your own circumstances. Tax and payroll rules change: check the current position with the authority or your adviser.
