1. Dear Bernard, this is all most unusual. Essentially, for this solicitor or your sister to have authority to act in relation to your father's affairs he would have had to make an Enduring Power of Attorney during his lifetime which covered the situation when he lost mental capacity. Otherwise, no one else has power to act in his affairs whilst he has dementia. As I gather from what you say, your father did not make such arrangements whilst he was of full mind and before he got dementia. Accordingly, unless your sister or this solicitor produce an Enduring POwer of Attorney which gives power over your father's affairs whilst he is alive, they have no ability to touch his bank accounts. The only other possibility is that your father was made a WArd of Court unbeknownst to you. However, there is a requirement when made a Ward of Court that all members of the family be informed. Accordingly, my first impression is that both your sister and this solicitor are here acting unlawfully in what they are doing. I would advise you to make further inquiries.