What is the question that your own insurer is going to ask?
If it's "Have you had any claims in the last five years?", then your answer is no as your company is claiming, not you.
If it's "Have you had any accidents in the last five years?", then your answer is yes as you clearly have.
If it's "Have you had any accidents or claims in the last five years, or anything else that could effect how we register your risk?", then see above.
Just tell them regardless. They'll either not care (0.001% chance) or they will be very interested and adjust your premium to suit. If you don't tell them then you are holding back a material piece of information, much as if you didn't declare the 22" rims and three turbos you have installed to your car.