my father has an illegitimate child abroad

my parents are married for 26yrs now. my father went to hong kong when i was 4 yrs old. to support us and now im 25. but last year a text to my mom shocked us all. "hndi kna nya mahal, may anak na kmi ni R dito." (something like this). since that happened my father tends to give us not enough to support us anymore. my younger sister is still studying and now we are really short. we cannot pay the bills on time, my mom filed loans that is due already on almost everything we have. my father even asked my mom to give him money because he has also debts there in hk.

my mom told me that the woman whom my father has living with in hk has a contract for domestic helper and instead finishing it my father paid the contract in hk.

my consultation is what are the possible cases my mom can file to my father?

sana maadvisan nyo ako kasi po mkikisbay po ako sa friend ko na pupunta ng hk sa wed. titignan ko po status ng tatay ko dun at kung mgkakaroon ng chance na mguusap kmi.
my father nga pla is a resident in hk at pagkakaalam namin iniisponsoran nya ung kinakasama nya.
salamat po.

econ abuse under ra 9262 if he is no longer sending support. but dont expect much to happen if he's not here.