Pale Rider
Legendary Member
Your brother will have had a fiduciary duty to your Mum. It seems like me might have not carried this out properly, even getting your Mum to sign the Power of Attorney under duress or exerting undue influence. If she was suffering from dementia or the onset of it, then I think with advice from a doctor that this was the case so she might not have understood what she was signing, would mean that you could challenge what your brother has done. The rules may have changed some what since was involved with such cases as there were two types of Power of Attorneys basically medical and financial. Not sure if this is still the case. One of the witnesses had to be a medical professional if there was any indication that the person making the Power of Attorney was of unsound mind and iirc the Court of Protection would be involved. If your brother has done anything untoward and there is evidence then criminal sanctions can be quite severe. If he has assets then monies he has obtained illicitly can be clawed back.
HTH.
I think @Crankarm is correct about changes.
My older brother made me and other brother power of attorney while he was of sound mind, so that might be different again.
But I formed the impression the power we have, or at least the process to create it, is a recently streamlined one.