I have been called as a witness in an HMRC smuggling investigation.  Neither me nor my employer is implicated, I'm just called to explain my company's position and explain what happened with paperwork, but they have said they need to do a witness check on me before they submit the case to the CPS.  My conviction is spent, and all they asked for is my name, DOB and address, but I am concerned my conviction will come out and my employer could be told ...

Does anyone have experience of this please ?  DBS website asks for a proof of id and they haven't so is it a simpler check of some sort ?

Finally any advice on how I respond if they find my spend conviction and want to disclose to my employer ? I'm thinking a) they can't and b) I argue its irrelevant ?
Any thoughts gratefully received