These are both examples of the British child services, the supposed "child protection" either directly sexually exploiting the children (their employees getting paid to pimp out vulnerable children), or helping others do that (not stated as such, but let's be realistic here, they were also getting paid for it).
As for the involvement of immigrants in both cases the immigrants came from former commonwealth countries (since child services pay is total shit, they hire immigrants. Even those don't last, so they're fresh immigrants with often very limited language skills, never mind actual training in caring for children. That this is a horrible idea as it removed children even further from their known environment, which is bound to damage them further, doesn't matter to anyone).
But none of it has anything to do with Europe. Only 1 out of 32 involved immigrants may have had something to do with Europe (the Afghan, as allowing that immigration is an EU policy). Pakistani immigrate under British law.
So does this have to do with Europe ? Child protection services in the UK, like everywhere else, is a cesspool of misery, locking children up, despair, desperate poverty and abuses of power. But the UK service is very much British.
So what does it have to do with Europe ? What does it have to do with Brexit ?