Would the Zakah-giver become free from obligation if the one entrusted to convey it betrays the trust?

I have a poor brother to whom I liked to give the Zakaah of my property. Out of keenness on his benefit, I sent the money to my eldest brother to buy a car for him (for my poor brother) to work with rather than spend the money in useless things. But my eldest brother took the money for himself and did not give it to my poor brother, even though he knew well that it was Zakaah. I came to know about this only recently. In this case, have I fulfilled the obligation of Zakaah? I have demanded the money from him in order to give it to my poor brother, but he is procrastinating.

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad , is His slave and Messenger.

In order for Zakah to be valid, the scholars put the condition that the recipient should be enabled to own it. According to Al-Hijjawi Al-Hanbali if it (Zakah) is damaged in the hands of a deputy before it is conveyed to the recipient, its surety lays upon the property owner who should guarantee it; and in order for it to be valid for the almsgiver, and for the poor to own it, it must be given to the poor himself. That the surety of Zakah lays upon the owner of the property in case of damage in the hand of the deputy goes back to the failure to realize the meaning of giving enjoined by Allaah in His saying (what means): {and give Zakah.} [Quran 2:43]

Thus, it should be known to the questioner that he is still liable for Zakah, and it is due on him to take it from his brother who usurped it or to pay it again.

Allaah Knows best.