Does the verb "dire" take a direct object or an indirect object ?

Both, actually. What you say is the direct object and to whom you say it is the indirect one. 

Je lui ai dit de bonnes nouvelles. - I told him some good news. 

Merci Chris 

So in this example quoted by you ,"de bonnes nouvelles" is the direct object as it just comes after the verb without any preposition 

Am I correct ? Please justify 

Yes, "de bonnes nouvelles" is the direct object.

Merci beaucoup Chris pour votre réponse