Is it permissible to buy a football or basketball made from the skin of an animal not slaughtered according to Islamic law, and to play with it?

The summary of the answer: The leathers used in the manufacture of soccer or basketballs are tanned. To know the ruling on their use, the type of animal must be identified:

a. If the animal is edible (like cattle), tanning its hide purifies it and it is permissible to use it, even if it was carrion.

b. If the animal is inedible (like a pig), its hide remains forbidden for use even if it is tanned.

The preponderant opinion is that the hide of carrion becomes pure through tanning if the carrion is from an animal whose meat is permissible to eat (i.e., an edible animal). As for the hide of an animal whose meat is forbidden to eat, it does not become pure through tanning. Based on this, it is permissible to buy and use balls made from the hides of edible animals, as tanning their hides makes them pure.