Ketubot, Chapter Two, Mishnah Nine
As we have mentioned before, if a married woman was raped she may return to her husband but only if he is an Israelite. If he is a priest, she is forbidden from returning to her husband. If she willingly had sexual relations with another man, the she is forbidden to her husband, even if he is only an Israelite.
1) A woman was imprisoned by non-Jews:
a) if for the sake of money, she is permitted to her husband,
b) and if in order to take her life, she is forbidden to her husband.
2) A town that has been conquered by siege-troops: all the priests wives who are in it are prohibited [from their husbands].
a) If they have witnesses, even a slave, even a female slave, they are believed.
b) However, no one is believed as to himself.
1) Rabbi Zechariah ben Ha-katzav said: By this temple! Her hand did not move out of my hand from the time that the non-Jews entered Jerusalem until they departed.
2) They said to him: No one may testify concerning himself.
Section one: When a woman is imprisoned by non-Jewish authorities, there may be a fear that she had relations with one of them. According to our mishnah, if she was taken in order to collect money, the captors assumedly did not have relations with her, because they would fear that if they rape her they will not get the money they want. In this case, she is not prohibited to her husband, even if he is a priest.
However, if they took her and intended to execute her, and then she somehow escapes or is let free, she is prohibited to her husband, even if he is an Israelite. The concern is that in order to endear herself to her captors, she willingly had sexual relations with them.
Others explain this clause to refer only to the wife of a priest. If she was taken for monetary gain, they did not rape her and she may return to her priestly husband. However, if she was seized for execution, the captors would not hesitate to rape her and she is forbidden to her husband the priest. According to this explanation, there is no concern that she willingly had relations with her captor(s) and therefore, if her husband was an Israelite she is in all cases permitted to him.
Section two: If a city has been captured by foreign soldiers, there is concern that the women of the city were raped. Therefore, all of the women married to priests are forbidden to their husbands. However, if a woman has a witness who can testify that she was not raped, even if that witness is a slave or a female slave, the witness is believed and the woman is not prohibited to her husband. What is not allowed, is for a woman to testify about herself or for a husband to testify about his own wife. This is illustrated by the story of Rabbi Zechariah ben Hakatzav, who swore an oath by the Temple that his wife was with him the entire time that the city was occupied by the foreign troops. The other Sages responded to him that a person cannot testify about himself, and since this testimony effects him personally, he is not believed.
The Talmud notes that if in the city there was a hiding place, all of the women are permitted to their priestly husbands, even if the hiding place could only fit one person. This is because each woman could claim that she was in the hiding place. Therefore, even if she says is I wasnt raped she is believed because she could have said, I hid.