they are not part of statutory audit or internal audit.
A forensic audit is an examination and evaluation of a firm’s or individual’s financial information for use as evidence in court. A forensic audit can be conducted in order to prosecute a party for fraud, embezzlement or other financial claims.
So as per above definition it is like Investigation and not audit.
Formerly known as Electronic data processing (EDP) audit, an IT audit is the process of collecting and evaluating evidence of an organization’s information systems, practices, and operations. Obtained evidence evaluation can ensure whether the organization’s information systems safeguard assets, maintains data integrity, and is operating effectively and efficiently to achieve the organization’s goals or objectives.
So as per above definition it is focused on how IT systems in company is working, is data of entity safe and secured.