This sounds like a difficult situation. While your mother was living, your brother may have been acting for her under a power of attorney or as a joint owner. He did not become an executor until she died and he was appointed by the court, if that has happened.
I don't understand how he can remove you from her bank account, but maybe you just had check-writing authority and he unauthtorized that as your mother's agent. If he was a joint owner of the account and deposited the house sale proceeds into it, they became his funds solely when she passed away. If this is the case, this is not an issue of how he is administering her estate but of his misdeeds while she was still alive.
I certainly would request, in writing, an accounting of the last couple years of her life to include the house sale and any loans to him. If he does not comply, you can begin a legal action against him alleging that he either misappropriated your mother's money or unfairly pressured him to give it to him. You will need a lawyer for this. As part of the suit, you can require him to provide you with all of the banking and other records. Good luck.
Answered on Feb 24th, 2017 at 6:26 AM