How to load a .fbx file containing multiple submeshes into the scene by scripting?

Guys,

Good morning. I'm trying to load by script a fbx file (see image, in red) which contains multiple submeshes (in blue: default_mesh_01, default_mesh_02,...) into my scene. The problem is that when I do this only the first submesh is loaded.

How could I load the complete .fbx file (containing all the submeshes) into a GameObject with its corresponding childs into the scene? Should I focus this from other point of view?

The code is this

 //Load 67P mesh
 Mesh _mesh_init  = Resources.Load("Meshes/67P_fbx",typeof(Mesh)) as Mesh;
 _67P_material = Resources.Load("Meshes/Materials/67P_material",typeof(Material)) as Material;
 //Create the GameObject
 _67P_3Dobject = new GameObject("67P");
 _67P_3Dobject.AddComponent<MeshFilter>();
 _67P_3Dobject.AddComponent<MeshCollider>();
 _67P_3Dobject.GetComponent<MeshFilter>().mesh = _mesh_init;
 _67P_3Dobject.AddComponent<MeshRenderer>();
 _67P_3Dobject.transform.localPosition = _67PPosition;
 _67P_3Dobject.transform.Rotate(_67P_T0_Rotation);
 _67P_3Dobject.transform.localScale = new Vector3(scale,scale,scale);
 Renderer renderer = _67P_3Dobject.GetComponent<MeshRenderer>().renderer;
         renderer.material = _67P_material;