No, you do not have to reveal your name or any of your details. It is important to remember though that in some cases (for example where you are personally affected) you may be encouraged to provide your personal details.
These are your options:
Provide your personal details which will be passed on to ISG;
Provide your personal details to KPMG Ethics Line, but request that these are not passed on to ISG; or
main totally anonymous (do not give the call centre agent any of your personal details).