Were brom and morzan brothers

As far as we know from the three books that have been released Brom and Morzan were not brothers. Oromis tells Eragon that Brom met Morzan while Brom was training to become a rider. However, this doesn't mean that they definitely are not brothers as they could have been separated at birth. I do not believe that they are because Paolini has given no subtle indications of that type of relationship, and there is usually gratuitous amounts of foreshadowing in his writing.

Actually, they are brothers by marriage because Selena had Murtagh with Morzan and Eragon with Brom so technically they are brothers by marriage