The original one. I get that it was deployed as a measure to undercut the Krogan fertility and their ability to replenish the army, but it would have had the same effect without disclosing that it was artificially created, or who deployed it. As a result of this information being public, Krogan hate the Turians and the Salarians, and go out of their way to harm individual members of these races given the chance to do so. I would think it would've been prudent to keep Krogan in dark on the subject of origins of genophage, so as to not cause unnecessary animosity in already bitter Krogan. Given how pragmatic Turian and Salarian governments are I would hazard a guess that they would do exactly that.
So my question is, who was the bleeding-heart pinko that blew the whistle on the whole thing?
It would be pretty obvious that it was artificially created, and it would be pretty obvious who had the motive and technology to do it and the ability to deploy it. They could deny it all they wanted, but it would be laughable as a lie.
Here's what I mean - consider the HIV virus. It was not artificially created, and it is quite easy to prove this. Not only can the genetic ancestry with SIV be traced and mapped, but a large number of mammalian species have similar immunodeficiency retroviruses. They are ubiquitous in nature. Thus, HIV quite obviously jumped the (relatively minor) species barrier.
But an artificially created virus - it would come out of the blue. There would be no similarity with natural viruses, and it would be extraordinarily efficient. That doesn't just happen. Once the genophage was identified as a virus, it would be very easy to deduce that it was artificially created, and very easy to deduce who the likely culprits were (*cough* Salarians *cough*). So they could lie, but the whole galaxy would know it was a lie.