This Long Statement is given when the Police question you about the facts and circumstances of the case with which you may be acquainted. You are bound to answer truthfully, i.e. you cannot lie. However, you have a right to choose not to make a statement with regard to any matter which will expose you to a criminal charge. You can ask for permission to talk to your lawyer before giving a witness statement, but your request may be rejected if it interferes with investigation.
Your lawyer should request for a copy of your witness statement to be disclosed at the Criminal Case Disclosure Conference (CCDC).