The FCA said the firm claimed its maximum charge applied to an individual client was 5% of their portfolio value, however the FCA found fees “far in excess of this.”

The regulator said some clients, including some with vulnerabilities, were paying fees “exceeding 65% of the value of their portfolio” significantly reducing the value of their investments.

The FCA began to investigate the firm following responses to a recent sector-wide wealth management data survey.

The FCA restrictions imposed today mean the firm cannot undertake any regulated activity, charge any further fees to existing clients or take on new clients without express FCA permission. The firm has also been ordered to withdraw all financial promotions and keep assets in the business.

During its enquiries the watchdog also found the firm transferred £1.3m from its bank account. The FCA said: “We believe the firm may not have communicated openly or honestly with us, their regulator.”

The FCA said it had “significant concerns” about the firm which it ordered to stop taking fees from clients in April.

The firm was set up in 2008 and listed its office at an address in Royal Exchange in the City of London. Its website appears to be replaced today by details of the FCA notice.

In a statement today the FCA said: “This (action) follows serious concerns about London Stone Securities Limited not delivering good client outcomes. The firm was charging excessive fees, which do not appear to be justified, clearly relate to benefits for the firm’s clients or provide fair value.

“Low value investment portfolios were particularly affected. In addition, charges were not communicated to or agreed with all clients in advance, raising concerns that the firm has not appropriately disclosed and explained its service terms.

“This risk was exacerbated as some of the firm’s client base have characteristics of vulnerability. We are also concerned London Stone Securities issued financial promotions which did not follow our rules that appear to have directly targeted potential clients who were elderly, disabled and vulnerable. We also found inconsistencies in information the firm provided to us.”

The FCA said that having considered representations from the firm, it considers that the restrictions should remain in force due to the seriousness of the potential consumer harm the firm has caused. The firm has the right to challenge the action and refer the matter to a tribunal.