An advisory panel on the Imperial system said Tuesday that allowing a female to ascend the Chrysanthemum Throne should be considered as an option to avoid an eventual succession crisis.

The panel issued an interim report Tuesday amid rising fears that a looming shortage of male heirs could trigger a crisis unless the law is changed to allow females on the throne.

The panel said another option would be to bring back members of the old aristocracy -- or their offspring -- forced from the Imperial household in 1947 after Japan's defeat in World War II.