The Financial Conduct Authority (FCA) and City of London Police have arrested three people in connection with a fresh boiler room investigation.
The FCA arrested two men aged 32 and 41, and one woman, aged 32, on Tuesday morning, after executing search warrants at six addresses in Kent, Essex, and Bedfordshire.
The individuals were interviewed in connection with an investigation into boiler room activity, however no individuals have been charged, the FCA said.
The arrests are not linked to any other ongoing investigation, it added.
The FCA said it could not give any further details at this stage.
The regulator previously shut down a suspected boiler room scam in November by placing an unlimited worldwide asset freezing order on First Capital Wealth while banning it from selling selling investments regulated by the FCA.
Another fraud case, the FCA's first ever prosecution of accused fraudsters, stalled last year after barristers refused to represent the defendants.
It was only dealt a lifeline early this year by the Legal Aid Agency which sought to find a way around the fee-related problems that had rocked the legal industry.
Last week, the FCA warned investors of a new boiler room scam operating under the same name as authorised firm LBV Asset Management.
To promote 'long-term investment'
Switching 'hard and expensive'
Smaller funds still packing a punch
To drive progress