diff --git a/io_scene_obj/export_obj.py b/io_scene_obj/export_obj.py
index 34c6f7a08a77a1fc78bc511d7f004950e07639cf..594a4167bddd366c5b9175dc84fc515cef5c968a 100644
--- a/io_scene_obj/export_obj.py
+++ b/io_scene_obj/export_obj.py
@@ -45,22 +45,6 @@ def write_mtl(scene, filepath, path_mode, copy_set, mtl_dict):
     source_dir = bpy.data.filepath
     dest_dir = os.path.dirname(filepath)
 
-    def copy_image(image):
-        fn = bpy.path.abspath(image.filepath)
-        fn = os.path.normpath(fn)
-        fn_strip = os.path.basename(fn)
-
-        if copy_images:
-            rel = fn_strip
-            fn_abs_dest = os.path.join(dest_dir, fn_strip)
-            if not os.path.exists(fn_abs_dest):
-                shutil.copy(fn, fn_abs_dest)
-        elif bpy.path.is_subdir(fn, dest_dir):
-            rel = os.path.relpath(fn, dest_dir)
-        else:
-            rel = fn
-        return rel
-
     file = open(filepath, "w", encoding="utf8", newline="\n")
     file.write('# Blender MTL File: %r\n' % os.path.basename(bpy.data.filepath))
     file.write('# Material Count: %i\n' % len(mtl_dict))