Where, in any proceedings, the recoverable rent of a dwelling-house subject to a regulated tenancy is determined by a court, then, on the application of the tenant (whether in those or in any subsequent proceedings) the court may call for the production of the rent book or any similar document relating to the dwelling-house and may direct the clerk of court to correct any entries showing, or purporting to show, the tenant as being in arrears in respect of any sum which the court has determined to be irrecoverable.