My understanding is that Venezuela has provided some gasoline components, for which the U.S. applied a light sanction a year ago against Venezuela as well as a couple of other companies around the world, including an Israeli company. It was for providing gasoline components to Iran. That helps Iran, because Iran needs gasoline and doesn't refine its own oil.
The other concern has to do with banking, the financial sector, in terms of Iranian banks having access through Venezuelan subsidiaries to get around some of the attempts to control the financial capacity of Iran.
I have not seen the evidence, if any was presented, about some kind of support to the nuclear weaponry issue. I'm not sure what that would be from Venezuela, since they don't have capacity. There is uranium in the ground, but they're not producing yet.
I don't know what evidence there would be, I haven't seen it.