Is Corruption in Iran finally being addressed?

The arrest of Babak Zanjani is a significant event in Iran. Corruption in Iran is understood to be rampant; figures as significant as former Presidents Ahmadi Nezhad and Hashemi Rafsanjani have been accused of abusing their authority for financial and/or nepotistic reasons. In-fighting and factionalization in Iran is also a problem, with the various groups at odds with each other. If someone like Zanjani who allegedly has been instrumental in helping the Islamic Republic avoid US/EU sanctions has now fallen out of favor, one must wonder why this would happen now before the nuclear agreement between the P5+1 and Iran has not yet been applied? 

The sanctions relief scheduled to implemented under the new nuclear agreement has not started yet. One would think that someone who has supposedly been so important to the Islamic Republic's efforts in limiting the bite of international sanctions would not be thrown in jail, especially not at this stage. Was the alleged corruption so significant that Iran's government and economy would be better off without such an important businessman? Is this a sign that there will be efforts aimed at reducing corruption in Iran, or is this a personal vendetta or domestic political squabbling? President Rouhani is close to former President Hashemi Rafsanjani, who also has been accused of corruption amongst other criminal acts. Will Rafsanjani also be investigated for corruption or will his ties to the President exempt him?

Babak Zanjani's arrest is interesting and it remains to be seen if this is the first step towards a genuine attempt to eliminate corruption or if this is just political witch hunt like what happened to Russian oil tycoon Mikhail Khodorkovsky. I hope that this will be a step towards stopping corruption, and that Setad, the case exposed by Reuters, as well as any other abusers of the system will also be subject to investigation.