if for his own car, then the policy conditions are as soon as possible, or within a specified number of days/hours. an own damage, fire or theft claim will not be entertained 4 years down the road.
If a third party claim, that is someone else is claiming against your father, then if they have not done so within two years for injury they are out of time.
In law, they have six years to pursue a damage claim, but again, the insurers will refuse to deal with it given the time delay.
in a nutshell, for making the claim yourself, you are too late.