Is Police Commissioner Bill Bratton leveling with the public over the growing corruption scandal engulfing the NYPD?

He says he was briefed in 2013 — before he was sworn in as commissioner — about a federal probe into whether police officers accepted cash and gifts from two businessmen with ties to Mayor Bill de Blasio in exchange for favors. But Bratton has not said what exactly authorities told him.

That was also the year that Alex “Shaya” Lichtenstein — the man at the center of the latest corruption charges — began a scheme to bribe Pistol Licensing Division officers to score hard-to-get permits, according to a criminal complaint filed against him last week.

So far, the 2013 corruption claims involve nine chiefs and inspectors accused of accepting jewels, other freebies, and no-cost trips, including one with a prostitute on a private plane. The claims suggest the alleged corruption began under Bratton’s predecessor, Ray Kelly, if not before.

But the case also indicates that in the two years since Bratton says he learned of the probe, the alleged corruption went unchecked. Lichtenstein’s dealings with the division continued at least through the end of last year, according to the criminal complaint. He apparently visited headquarters twice a week to meet with division officials. From the officials, Lichtenstein allegedly obtained 150 gun permits for, among others, the Borough Park Shomrim, a controversial Hasidic civilian patrol unit. One of the permits allegedly went to someone who had been the subject of four domestic-violence complaints, including one in which he threatened to kill someone.

Despite his claim that he was briefed, Bratton seems have been in the dark about what is happening at the NYPD and the federal investigation. He has been immersed in anti-terrorism measures and the fallout from the “chokehold” death of Eric Garner in Staten Island over the past two years.

Where was the supervision while all this was allegedly going on? Where was Chief of Department James O’Neill? Where was Chief of Patrol Carlos Gomez?

And what of Bratton, himself? What exactly did the feds tell him? The old Watergate question directed at President Richard Nixon must now be directed at him: What did he know? And when did he know it?