Legal advice is essential.
If you have reason to believe that you are under criminal investigation by HMRC it is essential that you obtain advice from an appropriately experienced criminal lawyer. It is usual then for the lawyer to appoint specialist tax advisers to advise on the technical tax issues.
At Covertax we are not lawyers, but we have considerable experience in assisting defence lawyers on tax-related issues. Also, if you need legal advice but haven’t yet appointed a lawyer we may able to help you to find a suitable representative.
It is vital to act with urgency.