Customer compliance interview

Hi am wondering if any one can give me some information, I have recently had a letter asking me to come in for a customer compliance interview, I have no idea why and I am so nervous. I have a 6 month old baby and been on Benift since Feb 2015 which I split with my ex partner shortly after. My partner still comes round to see the baby and stays up to 2 nights a week as he doesn't want to miss out on the baby why he is so young, he lives at his mums otherwise. Also they want bank statements what worries me is my ex partners step dad helps me with rent as I can not afford it on my own. Would this look strange to offercers? I may be over thinking he whole thing but it is very scary.