Acting in conjunction with the West Midlands Police the City watchdog executed search warrants on three premises in the region, leading to the arrest of two individuals.
The individuals are suspected of providing financial advice when not authorised to do so and of making misleading statements to investors.
The FSA said at this stage nobody has been charged in conjunction with the investigation, which is still on-going and no further details about the firms or suspects can be provided at this time.
Under the Financial Services and Markets Act 2000 (FSMA) persons providing financial advice or arranging deals in investments must be authorised to do so and contravention is a criminal offence punishable by fine or imprisonment of up to seven years.
Also under provisions in FSMA, making misleading, false or deceptive statements is punishable in the same fashion.