99.—An annuity at any time outstanding may, if the housing authority entitled to receive the annuity think fit, be redeemed by the person liable to pay the annuity by payment to the authority of such amount as may be approved by the Minister, and the premises, which but for this section would be subject to and charged with the payment of the annuity or the part, shall, on receipt by the authority of the amount so approved, stand freed and discharged from the payment of the annuity.