Prayer: Is Prayer Valid While Wearing Doubtful Leather from Non-Muslim Countries?

Practical Laws of Islam as per the teachings of Imam Khamenei

Prayer: Is Prayer Valid While Wearing Doubtful Leather from Non-Muslim Countries?

English:

Question #427:

I purchased a leather belt from Germany. Is there any shar‘ī problem in performing prayers with it if I doubt whether it is made of natural or synthetic leather or whether the leather belongs to an animal that is slaughtered ritually? And what is the ruling with respect to the prayers that I performed while having the belt on?

Answer #427:

If you doubt whether it is made of natural leather or not, there is no problem in performing prayers with it on. But, if you know it is made of natural leather but doubt whether it is from an animal that was ritually slaughtered or not, even though it is ruled as pure, it is unlawful to pray in it. Nevertheless, the prayers performed in the past are considered valid and there is no need to make them up if you were ignorant of this ruling.

-Imam Khamenei, Practical Laws of Islam, Importance and Conditions of Prayer