Irrlicht Engine

Hello.I know,i can bore you . I have some questions.
Can i use models(created by a fan,not from original game) of a game mod on my commercial game?
For example: I found 3d models of a Civilization 4 mod

I couldn't find a copyright text.
http://forums.civfanatics.com/showthread.php?t=239127

Another question : If i can't use them on a commercial game, can i use them on free(but not open-source ) or open-source game ?

NOTE:I can buy from an online store.But these models are very good,animated and free.

Thanks,thanks,thanks

ask the creator

Thanks.I asked.He didn't answer yet.But i think they are reskin of the game models.Can i use them?

Default in copyright is usually that the owner has all rights. And licenses are the way in which the owner can tranfer some of the rights to other people.

So you need a valid license which explicitely allows you to use stuff like textures and models for your specific case. Unless you have those you can't use it.