If brothers solicitor refuses to release copies of property title and gift deeds jointly owned by both.Remedy?

For three years now, despite requests by many solicitors he refuses to release full doentation ,even though giver ( now senile) always wanted both to share equally.Solicitors suggest certain doubts persist as to the validity of the bequest and this works to the advantage of the brother who exercises exclusive power of attorney to use all his mothers authority in his favour.It appears brothers solicitor made "mistake" in following her instructions but will not release for independent proof. Public Guardians Office wasted all her money and mine yet still not resolved my objection to his tyranny.