If rents are collected during the redemption period and the property is redeemed under this act prior to the expiration of the redemption period, the accumulated rentals shall be delivered to the owner or a legal representative less any cost incurred by the deposed purchaser for collection of income or for improvement and maintenance of the property during the period in which the purchaser was entitled to the property unless the tenant of the city was the redeeming owner or his lienor.