Would I be able to employ a Private Investigator in the following way?

There’s a long history to this question which I won’t bore you with but suffice to say that this issue is very close to my heart and I have tried everything else.

My son is four and his father hasn’t seen him for over two years. He never calls, sends cards or letters or anything. Although he does sporadically pay maintenance through the CSA they don’t hold a fixed address for him. The relationship between us is completely broken down despite me trying to make things right for a long time.

I have accepted that there is nothing I can do to make him want to be involved in my son’s life but I want my son to be able to find him if and when he wants to. My fear is that he won’t be able to because we don’t know now and certainly won’t know in many years to come where he is.

So, could I employ a PI to find and keep a track of his Dad over the coming years and if so how much would this cost me…around about? Do they even do this kind of thing?

Thanks for responses in advance x