There's no such indication. Quite the opposite in fact; there is indication in the books that the Eastern Dwarves were not under Sauron's domination.
One example is that the War of the Dwarves and the Orcs is noted to have involved all of the Dwarf families, as Lord of the Rings Appendix A notes:
Thráin at once sent messengers bearing the tale, north, east, and west; but it was three years before the Dwarves had mustered their strength. Durin's Folk gathered all their host, and they were joined by great forces sent from the Houses of other Fathers; for this dishonour to the heir of the Eldest of their race filled them with wrath.
This confirms that the Dwarves were united, and that the Eastern Dwarves did fight against forces of Sauron. This is also supported by the essay Of Dwarves and Men (in History of Middle-earth 12), which also introduces the concept that the Dwarf families were in communication with each other:
Though these four points were far sundered the Dwarves of different kindreds were in communication, and in the early ages often held assemblies of delegates at Mount Gundabad. In times of great need even the most distant would send help to any of their people; as was the case in the great War against the Orcs (Third Age 2793 to 2799).
Additionally, the essay Of the Rings of Power and the Third Age (in the Silmarillion) notes that Sauron failed to dominate the Dwarves with the rings he gave them:
The Dwarves indeed proved tough and hard to tame; they ill endure the domination of others, and the thoughts of their hearts are hard to fathom, nor can they be turned to shadows. They used their rings only for the getting of wealth; but wrath and an over-mastering greed of gold were kindled in their hearts, of which evil enough after came to the profit of Sauron.
So the most likely explanation is that these were just Men, and that nothing significant should be read into the "not tall, but broad and grim, bearded like dwarves, wielding great axes" description.