Except in the case of fraud no person contracting or dealing with or taking or proposing to take a transfer from the registered proprietor of any registered interest shall be required or in any manner concerned to inquire or ascertain the circumstances in or the consideration for which the registered proprietor or any previous registered proprietor of the interest in question is or was registered or to see to the application of the purchase money or any part thereof, or shall be affected by notice, direct or constructive, of any trust or unregistered interest, any rule of law or equity to the contrary notwithstanding; and the knowledge that any such trust or unregistered interest is in existence shall not of itself be imputed as fraud.