The Financial Conduct Authority (FCA) is concerned about execution-only, or non-advised, sales and the commission payments that such transactions are still allowed to collect.
Minutes of the regulator's June board meeting, which were published on Friday, revealed that the regulator's board was concerned that there needed to be a clear distinction between advised and non-advised sales.
It was concerned particularly about those features that could confuse consumers, such as decision trees on websites.
The FCA is also worried about the fact that websites selling investment products under the execution-only banner were still allowed to collect commission on those products up until the proposed trail ban in 2016.
The board was discussing "whether the continuation of commission payments for non-advised retail investment sales created potential risks".
IFAonline revealed last week that the adviser community was split over whether execution-only platforms were infringing the advice boundary and needed to be regulated or whether they were a good source of complementary business for advisers when dealing with lower net worth clients.
Personal Finance Society chief executive Keith Richards and Association of Professional Financial Advisers director general Chris Hannant both said they expected the regulator to look closer at the issue.
However, Ascot Wealth Management managing director Mark Insley said he hopes to be able to launch an execution-only platform for sub-£50,000 clients by the end of the year.
The FCA board minutes also showed that the regulator is deliberating over whether to put an end to pre-Retail Distribution Review (RDR) trail commission, in particular "whether the lack of end-date for the payment of trail commission on pre-RDR business might lead firms to act in ways that risked poor consumer outcomes".
Furthermore, the FCA was trying to determine whether there was in fact an advice gap and how big it is. According to the minutes, the regulator is toying with the idea of analysing the "calculations underpinning the estimated cost of distribution for the banks/insurers that had recently withdrawn from providing mass-market advice".
Another area of concern was the clarity of adviser charging and whether consumers were being led towards buying products under contingent charging models, as outlined by the FCA in its first thematic review into RDR implementation last month.
The board concluded the issues needed closer monitoring and would be assessed in a post-implementation review in 2014.
It said: "The executive explained that there would be a post-implementation review in 2014 when the RDR had been in place for an appropriate period.
"Success measures for the policy had been published and these would be reviewed to ensure they were appropriate. The executive would design and undertake thematic reviews to cover some of the issues highlighted and return to the board in Q1 2014."