Sayyed Mohammad Al-Musawi, Sayyed Mohammad al-Musawi is originally from Iraq and heads up the World Ahlul Bayt Islamic League in London. Other than being involved in various humanitarian projects, he frequently responds to... Answered 3 months ago

It depends whether the food is Najis or not. Najis food is not permissible to consume whether from a Muslim or non Muslim. Najis food means any food which was touched with wetness by a non Muslim (except People of Book according to some Maraaji').

If you know that the food is Najis, it will be not permissible for you to eat it at all.