The law in our country allows for a presumption – a presumption of death – in case of missing persons. If a person is unheard of for a period of seven years, he is presumed to have died and the onus of proving that he was alive within this period is on that person who affirms that he was alive.

Check this article for more details - http://www.policywala.com/what-to-do...-goes-missing/