First of all, it should be clear that in Islam, it is not only considered haram (forbidden) to consume what is haram, but it is also haram to promote, condone, aid, or assist the same.
The eminent Muslim scholar and renowned Da`iyah, Sheikh `Abdel Khaliq Hasan Ash-Shareef, states: “As far as Islamic Shari`ah is concerned, the basic ruling is that a Muslim should stay away from all doubtful and haram matters. You should recognize that the accountable (mukallaf) Muslim is commanded to enjoin what is good and forbid what is evil. So, the basic ruling is that you should avoid working for such places.