Sheikh `Abdul-Majeed Subh, a prominent Azharite scholar, states: “It is not permissible to make use of any haram animal except the skin of animals after tanning it. So, it is not permissible to make use of the meat or the fats of haram animals such as the dead animals. As for the meat of the pig, it is prohibited whether the pig is slaughtered or dead. As for its fat, the majority of Muslim jurists are of the opinion that it is prohibited to make [external] use of it in producing materials such as soaps, etc.”
Moreover,Sheikh M. S. Al-Munajjid, a prominent Saudi Muslim lecturer and author, states: “With regard to the ruling on using fats from haram animals in manufacturing soap, etc., there is a difference of scholarly opinion, but it is most likely the case that they are prohibited (haram) and we are not allowed to use them.”
Sheikh Al-Munajjid adds: “If the fats come from an animal that we are permitted to eat, then they come under the same ruling as the meat of that animal.
If they come from an animal which it is haram for us to eat – such as pigs – then we look at whether they are used in foods or for other purposes.
If they are used for non-food purposes, e.g. many fats are used in making soap, then there is a difference of scholarly opinion, but the most correct view is that they are haram.
If they are used in foods, e.g., pig fat (lard) is used in making sweets and other foods, this is haram.”