The receiver may employ such counsel and procure such expert assistants and advice as may be necessary in the liquidation and distribution of the assets of such bank and may retain such of the officers or employees of such bank as he may deem necessary. The receiver and such assistants as will have charge of any of the assets of the bank may be required to post such security for the faithful discharge of their duties as the receivership court may deem proper. The compensation of assistants and other employees and all expenses of supervision and liquidation shall be fixed by the receiver subject to the approval of the receivership court on notice to such bank.