54. When an owner has obtained unilaterally from the administrator, under section 53, authorization to rent a house to a new lessee at a price higher than that which was exigible from the preceding lessee, without the new lessee having been summoned or called before the administrator to attend the hearing of the owner’s application for authorization, the new lessee, if he has reason to believe that the rent authorized in his absence, upon the unilateral evidence of the owner, is excessive, may apply to the administrator for the reduction thereof, by an application made within thirty days after taking possession of the house and upon such application, the administrator may revise his former authorization, or confirm or alter the same, and the rent fixed after such revision shall be the lawful rent exigible from the new lessee.