The Pensions Regulator in the UK has published useful advice on how to avoid pension scams: Protected content
The advice is as applicable to expats as to those living in the UK .
In particular, if you are British, take note of Point 3, and deal only with a Financial Conduct Authority approved advisor. You will be dealing with someone who is supervised, has appropriate qualifications, and you will have the benefit of a compensation scheme if things go wrong. None of these benefits apply to the local "advisers".