"Any adviser engaging in this activity is unlikely to have a 'public interest' or 'whistleblowing' form of defense and as such could find themselves in court, either criminal or civil."
Financial adviser Al Rush, who has lobbied on behalf of the steelworkers, said the FCA had been contacted over how their contact details had ended up in the hands of CMCs.
He said: "I know that some steelworkers have been contacted by CMCs. It is not too widespread, but a lot of them have been getting text messages.
"Nobody has taken a CMC up on it as far as I am aware, so the impact is rather small.
"At the moment the claims have been going to the FSCS but there are going to be a lot more going to the Fos."
Mr McPhun added the British Steel case was only the tip of the iceberg.
He said: "We have a number of claims relating to British Steel, but we have far more claims referring to other transfers from other schemes.
"We have clients across the board – self-invested personal pensions operators, financial advisers - in which it will start off as one claim and then you find the same CMC ends up with 30, 40 or 50, or even 100 claims.
"One of the things we are increasingly asked to do as lawyers is to audit clients’ files, because they are concerned that if a claim comes in they will be exposed."
The FCA stated it was not aware of this issue.
Jonathan Davidson, FCA’s executive director of supervision, retail and authorisations, said: "We see CMCs exploring a lot of different areas, starting to think about other areas in financial services - we have seen quite a lot [of them] moving into the high cost credit area and making complaints about high cost loans.
"I don't think I've seen evidence that there is a huge impact in the area of financial advice at the moment."