Should I call BLL methods directly into my Asp.Net MVC 3 Controller?

Question

I have a Business Object Layer that I use in a couple of other applications and I want to use it on my MVC application. My concern is more a design concern: Is it correct to have something like the following:

using Interface.MyOtherProject
public class MyMVCController: Controller
{
    [HttpGet]
    public string GetSomethingById(Int32 id)
    {
        return new JavaScriptSerializer().Serialize(MyObject.GetById(id));
    }

}

So the question would be can I do this, should I do this in the Model instead and return this string directly from the Model or should I rewrite my BLL into my Model. I read some of the answers with similar question but it is not still clear to me if I can or cannot (rather if I should or not). I do not want to break the pattern since I will be showing this project to some companions in school.

Thanks for the help!

Hanlet