All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
As it is known, the skin of pig is impure and it does not become pure with tanning according to the view of the majority of the scholars . Therefore, the shoes that are made from pig skin are impure and it is not permissible to wear it according to this view. Our view in Islamweb, is that the skin of pig becomes pure after tanning it and it is permissible to wear the shoes that are made of the skin of pig. However, it is more appropriate to avoid it and not benefit from it especially during the prayer as a way of being on the safe side and avoiding the difference of opinion. For more benefit, please refer to Fataawa 82164 and 84103.
Nonetheless, the fact that the two kinds of shoes are identical in color and shape does not mean that the shoes of your friend are also made of the skin of pig. You may ask the shop owner where your friend purchased the shoes.
Even if we presume that it is made of the skin of pig, your foot does not become impure just by touching those shoes and your acts of worship do not become void. Therefore, you should not have whispers. Even according to the view that the skin of pig that is tanned does not become pure, the jurists stated that if an impurity touches something pure while both of them are dry, then it does not render it impure. If an impurity is dry and a dry thing touches it, then the impurity is not transferred to it by this, but if it is wet, it renders the dry thing that touches it impure.
Contrarily, if the impurity is dry and it is touched by a pure wet or soft thing, then the impurity is transferred to it according to the view of many scholars . For more benefit, please refer to Fatwa 81546.