(CNN) – NBC evidently got conflicting guidance from federal and local law enforcement officials about the legality of displaying an empty gun magazine on "Meet the Press," according to statements by the agencies involved.
An official with the Bureau of Alcohol, Tobacco, Firearms and Explosives told CNN that he relayed information to NBC from the Washington Metropolitan Police Department that displaying an empty gun magazine was legal. Meanwhile, an MPD spokeswoman said her department told NBC such a display would be illegal.
It was not clear in what order NBC received the communications. NBC declined again on Thursday to comment on the matter.
On Sunday, "Meet the Press" moderator David Gregory used what he described as a 30-round magazine while asking National Rifle Association CEO Wayne LaPierre whether banning such magazines could help lessen the impact of deadly shootings. In the wake of the school shooting in Newtown, Connecticut, gun control advocates have been pushing for a limit on high capacity magazines.
Following the broadcast, several conservative columnists questioned the legality of possessing the magazine in the District of Columbia, which has strict gun control laws.
The ATF official told CNN on Thursday that a reporter with NBC News - not Gregory - called ATF last Friday to inquire whether it would be legal to have ammunition or an empty magazine on the set of the Sunday show, which is broadcast from Washington.
The ATF official said he reached out to officers with the MPD to ask if that was permissible.
"What was relayed back to me - which turned out to be a miscommunication - is ammunition was not legal unless (in the possession of an officer), but a magazine was not a problem," said the official, who passed along the information to NBC.
The detail about empty magazines being legal in Washington was apparently inaccurate. Possessing a large-capacity ammunition device, such as a magazine, is illegal in the District of Columbia if the device holds more than 10 rounds of ammunition.
The code also specifies the large-capacity devices are illegal, regardless of whether they're attached to a firearm. Gregory showed the magazine Sunday without a firearm attached.
"I don't know where the miscommunication occurred (at the MPD), but I do know that I passed along the information that I was told," the ATF official said.
"We didn't give anyone permission, but we just relayed the information," the official continued.
The official spoke on the condition of being identified only as an "ATF official" to speak freely about the story.
On Wednesday, a spokeswoman for the MPD said a representative for NBC inquired ahead of the broadcast about using the high-capacity magazine.
The department spokeswoman, Tisha Gant, said the police told NBC it could not use the magazine. Gant said the matter is under investigation.
NRA President David Keene said on CNN Thursday he didn't think Gregory should be prosecuted for possessing the magazine, calling the D.C. law "silly."
"There are two lessons for him there," Keene said. "Don't ask the government what's legal and what isn't legal, because half the people you ask don't know. And secondly, that's a silly felony. It's a felony in Washington, D.C., to own that magazine or to be caught with a cartridge. So I really think what David Gregory did, while he was inadvertently flaunting the law, was illustrated in a very graphic way, perhaps not intentionally, just how silly some of these laws are."
CNN's Kevin Bohn, Larry Lazo and Kevin Liptak contributed to this report.