A state Senate hearing into Spitzergate yesterday shed a bit of light on one of the sordid affair’s more mysterious elements: Why did Inspector General Kristine Hamann initially fail to reveal that her own probe of the case immediately encountered a fundamental conflict of interest?

Hamann believed the conflict to be so profound that she couldn’t finish her investigation, such as it was.

But she didn’t even speak of it – let alone step down and pass the probe off to Attorney General Andrew Cuomo.

And why not?

Because such a demurral would also have vested in Cuomo the subpoena power he needed to force Gov. Spitzer‘s aides to testify under oath.

In the event, Cuomo proceeded with his own probe, sans subpoena power. And when two key gubernatorial aides – Chief of Staff Richard Baum and Communications Director Darren Dopp – refused Cuomo’s request that they testify, the AG couldn’t do a thing about it.

Pretty convenient, huh?

Hamann’s “conflict” was that she reported to Baum, so it would have been impossible to investigate him. (Not to mention that Spitzer – whose own role in the affair remains dismayingly unclear – was the one who hired her in the first place.)

But when Hamann realized there was a conflict, she could have referred the case to Cuomo – and conveyed her own subpoena powers to him in the process.

Instead, her office went mum.

It didn’t investigate further.

It didn’t issue subpoenas.

And, again, it decidedly didn’t hand over its powers to Cuomo.

Rather, it just endorsed his report, incomplete as it was, knowing he hadn’t been able to compel testimony. Cuomo apparently never even knew Hamann faced a conflict.

“Prior to the issuance of this [the AG’s] report, I was unaware” of any conflict at the IG’s office, Cuomo’s counsel, Steve Cohen, said yesterday.

Yet, Cohen asserted, “if we had subpoena power, this investigation would be over.”

How pathetic.

Spitzer bragged about how he had asked Hamann to conduct an “independent” probe of the affair.

Obviously, it wasn’t independent.

Obviously, it wasn’t even a probe.

But there was a chance to get at the truth: Hamann could have handed the case to Cuomo, along with her subpoena powers. She didn’t.

Now the question is: Why not? What is it she doesn’t want her bosses – Baum and, yes, Spitzer – to have to say?

Spitzer and his handmaidens, including Democratic allies like Sen. Tom Duane (who objected to questions at the hearing), seem eager not to examine Spitzergate. But New Yorkers won’t be satisfied until the full truth is revealed.

Happily, a little more of the iceberg emerges with each passing day.