MongoCSharpDriver deserialize anonymous type

gistfile1.cs

    public class TempDataDocument
    {
        public string Id { get; set; }
        public string Key { get; set; }
        public object Value { get; set; } // Aquí puede ir cualquier cosa
    }
    
    public static void Main()
    {
        var client = new MongoClient("mongodb://localhost:27017");
        var server = client.GetServer();
        var database = server.GetDatabase("tests");
        var collection = database.GetCollection("anonymous");
        var document = new TempDataDocument()
        {
            Key = "key1",
            Value = new { Nombre = "Sergio", Twitter = "@panicoenlaxbox" } // Guardamos un tipo anónimo 
        };
        collection.Insert(document);
        var data = collection.FindAs<TempDataDocument>(Query.EQ("Key", "key1"));            
        /* An unhandled exception of type 'System.IO.FileFormatException' occurred in MongoDB.Driver.dll

        Additional information: An error occurred while deserializing the Value property of class MongoDb1.TempDataDocument: A document being deserialized to System.Object must be empty.*/
        Console.WriteLine(data.ToList().First().Value);
    }