Stop my sister from leaking mom’s Jamaican bank account

I will try to keep this initial contact succinct and as brief as possible. Through circumstance my mother who is a Jamaican over 80 years old, and resides in England as I do, unfortunately had need for surgery and has subsequently lost mental capacity – Dementia based. I am one of three children. Through obstinacy mother had not made a power of Attorney or a Will, she has a minor level of assets in Jamaica, land, shares and banking. She had expressed to all members of the family a set of instructions of who is to get what, by the way I do not want anything other than for her wishes to be delivered.

401(K) 2013 via Foter.com / CC BY-SA

Now, my older sister is plagued with ill health, and my younger sister was carer to our mother. I found that in the UK that her bank account had been pilfered which was to be used to pay for her residential care and my younger sister who is a current authorised signature on UK & Jamaican banking had taken the money not once but on multiple occasions without talking or agreeing this with other members of the family for her own personal gain. Although I had told her on multiple occasion this was illegal as our Mother had lost capacity. I and other members of the family have had to make good the deficit to the home. In an attempt to ensure the police were not involved we agreed that I would administer to our mothers business and welfare and my younger sister will continue to deal with her care. I have asked my younger sister for all our mothers’ paper work including material for Jamaican e.g. deeds and shares and banking information on multiple occasions and have not received them.

I found out recently, through another family member that my younger sister, does not intend to let me have the banking information as the monies are to be hers. Also she has passed the Jamaican asset information to a third party. This is against our mothers’ expressed wishes! Therefore I am left to look at alternative course of action, before she sells mother’s assets which are meant to go to other members. I again have no vested interest other than making mothers’ wishes whole.
I believe that the only way forward is to gain immediate guardianship in the Jamaican legal system on my mother’s behalf, gain control or freeze her assets, is this the correct course of action? Can you help or guide me? I don’t want to call the police on my sister but ideally to take another course of action to remove her from decisions.
There is as always a lot more data to be taken on board but this was a first contact and I did not want to create an overload as we need to deal with this matter urgently before things are sold and ‘criminal’ action may be required.

If it were possible to speak to you, I can call, SKYPE, Facetime etc. to you to provide further information at a nominated date and time this week? Or, if you could provide contact of a recommended alternative, I and other family members would be grateful.

I do need to stay relatively anonymous at this stage to protect others but the email address is live and active and belong to me. Thank you again in advance and look forward to speaking to you soon.
Shawna Ann