The FCA says a Sky News investigation may reveal "unlawful" action and urges social media companies to protect investors.
A former first-class cricketer and international umpire has told Sky News he fears he has lost more than £70,000 in a lockdown investment scam.
Barry Dudleston was persuaded to invest more than £50,000 last summer after seeing an advert carrying a fake celebrity endorsement for OFC Markets, an unregulated foreign exchange and crypto-currency trading platform.
Despite initially showing huge returns that saw the value of his investment apparently increase to more than £140,000, for nine months he has been unable to withdraw any funds and fears he will never get his money back.
His case highlights an increase in financial scams appearing online during the COVID-19 crisis, leaving investors vulnerable to losing savings and with little prospect of recovering their money.
Last June, the Financial Conduct Authority issued a warning about OFC Markets, which is registered in the US Marshall Islands in the Pacific but not authorised to offer financial services in the UK.
Presented with evidence of Mr Dudleston's case by Sky News, the FCA's director of enforcement said its operations appear to be "unlawful", and his treatment had "red flag" signs of being a scam.
Lockdown has offered scammers greater opportunity to target the uninitiated or the vulnerable online, and Mr Steward called on the government to strengthen its ability to act by adding financial fraud to the list of areas covered by the forthcoming online harms Bill.
Source: Sky News