(a) A marriage is prohibited and void from the beginning, without being so decreed and its nullity may be shown in any collateral proceeding, when it is between—
(1) a man and his grandmother, grandfather's wife, wife's grandmother, father's sister, mother's sister, mother, stepmother, wife's mother, daughter, wife's daughter, son's wife, sister, son's daughter, daughter's daughter, son's son's wife, daughter's son's wife, wife's son's daughter, wife's daughter's daughter, brother's daughter or sister's daughter;
(2) a woman and her grandfather, grandmother's husband, husband's grandfather, father's brother, mother's brother, father, stepfather, husband's father, son, husband's son, daughter's husband, brother, son's son, daughter's son, son's daughter's husband, daughter's daughter's husband, husband's son's son, husband's daughter's son, brother's son or sister's son; or
(3) any persons either of whom has been previously married and whose previous marriage has not been terminated by death or a decree of divorce.
(b) Any of such marriages may also be declared to have been null and void by judicial decree.