Washington (CNN) - Washington Metropolitan Police Department is investigating whether NBC's David Gregory violated D.C. gun laws when he displayed what he described as a 30 round magazine as part of an interview during Sunday's "Meet the Press."
A spokeswoman for the department said Wednesday that a representative for NBC inquired ahead of the broadcast about using the high-capacity magazine, which Gregory displayed while interviewing the executive vice president of the National Rifle Association.
The department spokeswoman, Tisha Gant, said the police told NBC they could not use the magazine, since possessing a large capacity ammunition device is illegal in the District of Columbia. Gant said the matter is under investigation.
On Sunday, Gregory used the device while asking the NRA’s Wayne LaPierre whether banning such magazines could help lessen the impact of deadly shootings.
"So here's a magazine for ammunition that carries 30 bullets,” Gregory said, holding up the black, rectangular device. “Now isn't it possible that if we got rid of these, if we replaced them and said well, you can only have a magazine that carries five bullets or ten bullets, isn't it just possible that we could reduce the carnage in a situation like Newtown?"
It's not known whether the magazine Gregory had in his hand was authentic or a prop.
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 devices are illegal regardless of whether or not they're attached to a firearm. Gregory showed the magazine Sunday without a firearm attached.
NBC's studios, from which "Meet the Press" is broadcast, are located within city limits. The network did not have any comment on the matter Wednesday.
In the wake of the school shooting in Newtown, gun control advocates have been pushing for a limit on high capacity magazines. Such a restriction is one of the items President Barack Obama mentioned last week when he announced an administration effort to curb violence.
"I don't believe that's going to make one difference," LaPierre told Gregory during the show.
Several conservative commentators first raised the issue of whether Gregory had broken D.C. law by using the magazine.
CNN's Mike Ahlers and Kevin Bohn contributed to this report.