Tragedy suffered by a girl whose mother’s husband does not fear Allaah
Question

                It is with sorrow that i ask this question.My friend has been raped be her father for many years.She was conceived outside her parent's marriage but they married following her birth.She revealed the rape after she got married.Her father is a religious man with a solid reputation.I ahve heard once that the father of an illigitimate child is allowed to have a sexual realtionship with her because in Islam she is not his daughter,kindly clear me on that matter
Praise be to Allah.
    If what is mentioned in the question is true, then what can 
    we say about a mother’s husband who is so despicable, vile and contemptible, 
    and who is lacking in religious commitment and transgresses the limits set 
    by Allaah? To Allaah we belong and unto Him is our return; there is no power 
    and no strength except with Allaah. 

    Does he not know that Allaah has forbidden a man to marry the 
    daughter of his wife with whom he has consummated the marriage? Allaah says 
    (interpretation of the meaning): 

    “Forbidden to you (for marriage) are: your mothers, your 
    daughters, … your stepdaughters under your guardianship, born of your wives 
    to whom you have gone in”

    [al-Nisa’ 4:23]

    Let alone committing immoral actions with her. Does this man 
    not know of the serious threat which Allaah issues and the painful torment 
    that awaits the zaani (adulterer, one who engages in unlawful sexual 
    relations)? Allaah says (interpretation of the meaning): 
“And those who invoke not 
    any other ilaah (god) along with Allaah, nor kill such person as Allaah has 
    forbidden, except for just cause, nor commit illegal sexual intercourse  
    and whoever does this shall receive the punishment.

    The torment will be doubled to him on the Day of 
    Resurrection, and he will abide therein in disgrace”

    [al-Furqaan 25:68-69]

    Does he not know that committing adultery with one's 
    neighbour’s wife is worse than committing adultery with any other woman? It 
    says in the hadeeth that ‘Abd-Allaah (may Allaah be pleased with him) said: 
    “I said, ‘O Messenger of Allaah, which sin is the worst?’ He said, ‘Setting 
    up a rival to Allaah when He has created you.’ I said, ‘Then what?’ He said, 
    ‘Killing your child so that he will not eat with you.’ I said, ‘Then what?’ 
    He said, ‘Committing adultery with your neighbour’s wife.’” (Narrated by 
    al-Bukhaari, al-Hudood, 6313).  
Committing adultery with 
    one’s neighbour’s wife is regarded as a greater sin than committing adultery 
    with any other woman, so how about committing zina with someone who is his 
    mahram and is forbidden to him, as this evil man has done?

     Ibn Abi Shaybah said: Question on committing zina with a 
    mahram: Hafs narrated from Ash’ath from ‘Adiyy ibn Thaabit from al-Bara’ 
    that the Prophet  (peace and blessings of Allaah be upon him) sent him 
    to a man who had married his father’s wife, and ordered him to bring him his 
    head. Wakee’ narrated from Hasan ibn Saalih from al-Suddi from ‘Adiyy ibn 
    Thaabit that al-Bara’ said: “I met my maternal uncle and he was carrying a 
    banner. I said, ‘Where are you going?’ He said, ‘The Prophet  (peace and 
    blessings of Allaah be upon him) has sent me to a man who married his 
    father’s wife, to kill him, or to strike his neck.’” 

    Al-Musannaaf by Ibn Abi Shaybah, 
    part 8, p. 380. Also narrated by al-Nasaa’i, al-Nikaah, 3279; classed 
    as saheeh by al-Albaani in Saheeh al-Nasaa’i, 3123. 

    So how about if he forced this girl to do that, and committed 
    zina with her against her will?

     It is very strange that it says in the question that he is 
    very religious, even though he has audaciously transgressed the limits set 
    by Allaah. We ask Allaah to keep us safe and sound.

     One of the basic principles of Islam which no Muslim has no excuse for not knowing is that zina – with any woman at all – is haraam and is a major sin, and it is even worse if the woman with whom a person commits zina is one whom he is permanently forbidden to marry. We seek refuge with Allaah from the things that earn His wrath and painful torment.