The Financial Conduct Authority has issued three skilled persons reports in the first quarter of 2018 but has steered clear of pension and retail investment providers.
In an update published on its website on 1 August the regulator stated it had commissioned the reviews of a retail banking firm and two to wholesale financial market firms in the period.
Two of the firms reviewed were investigated for financial crime but the names of these firms have not been disclosed.
Figures published as part of the FCA's annual review last month showed the regulator had used its s166 powers 29 times in the year to April, meaning it asked 29 firms to commission an internal review of their business at their own cost.
In total, financial services firms were asked to fork out £83.3m for the reviews in the year.
Skilled persons reports are commissioned when the regulator has concerns over the activity of firm, with investigations into suspect firms carried out by third parties, which could result in firings or bans.
The reviews in 2017/18 examined a number of regulatory issues, including past business and quality of advice; adequacy of systems and controls, including the effectiveness of control functions; corporate governance and senior management arrangements; and financial crime.
They also included client money and client asset arrangements, risk management, including prudential risk, and complaint handling.
Conduct of business and financial crime related issues made up the bulk of the work, causing the launch of 10 and 11 reviews respectively, over the course of the year.