Sirius' wand

[tuck668]

No: HPFGUIDX 79309

While rereading OOP, I had this sudden revelation about Sirius. (I 
apologize profusely if this has been discussed. I've tried searching 
but the search engine is a bit iffy. If it has been discussed, I 
would be incredibly grateful if someone could point me toward those 
posts.)

When a wizard goes to Azkaban, especially for a life sentence, I 
assumed that their wand was broken, or at least confiscated in some 
way. Yet, in OOP, Sirius has a wand and it is never mentioned how he 
got it.

This could just be a minor detail that isn't worth explaining, but 
it has been bugging me for a few days. It seems unlikely to me that 
someone else bought him a wand, as it is, after all, the wand that 
chooses the wizard. 

Any comments?

-Anna