Did the Death Eaters buy that Sirius was one of them? He had no tattoo and never had any prior dealings with them. On top of that, according to public (mis)information, it was on Sirius Black's information that Voldemort acted on when he went to his demise.
According to this question, the accepted answer is that the Death Eaters were not yet aware that Pettigrew was on their side. I will hold this to be true for the purpose of this question, so any answers must take this into consideration.
Did any of them believe that Sirius was now on their side? Did they think he was a spy for the other side? Did any of them interact with him in Azkaban? (I thought I remember Sirius saying Bellatrix made some quippy family remark while inside, but I could be imagining it or worse, it might have been the movie encroaching on my imagination)