Today, I found out my stbxw went through our filing cabinets whilst I was out of the house doing the school run. She took the kids passports, birth certificates and Bank account books into a rucksack (which had been sat in our room for 3 weeks and suddenly disappeared this morning), and has hidden that under our sons bed (I looked around after she went out as something seemed off).

I don't know whether to take the documents and put them somewhere else, or just to leave them; she is trying to use "coercive control" as a form of domestic abuse against me, so worried if I take them that it will add more fuel to the fire... But I am also worried about her having that documentation and what she may do with it.

I can't talk to her about it; I noticed the filing cabinet unlocked when I got back from school, so asked what she had been after and she said "exam certificates" and failed to leave out the rest of the stuff. I can't trust a word she says anymore, so asking her about it is a pointless exercise.