The mayor of one New Jersey town in a region of the state that has seen its skies blanketed by drones over the past month believes he has solved the mystery of their origin.

“We know we have drones flying in a grid-like pattern. In my opinion, they’re looking for something. What might they be looking for? Maybe that’s radioactive material,” Mayor Michael Melham of Belleville said during a recent interview on Fox 5 New York’s “Good Day New York.”

The mayor referenced an alert issued by the U.S. Nuclear Regulatory Commission on December 2, in which they reported that radioactive material used for cancer treatments was lost after being sent out for disposal.

The NRC said in its report that the radioactive material in the diagnostic tool is minimal and does not pose a significant threat to the public.

“It was a shipment. It arrived at its destination. The container was damaged, and it was empty,” Mr. Melham said. “Information has not been forthcoming, and it’s this lack of transparency… that’s doing nothing but fueling conspiracy theories online,” he also said.

In a joint statement released on Monday evening, the Department of Homeland Security, the FBI, the Federal Aviation Administration, and the Department of Defense said they have poured over 100 notable leads from more than 5,000 reported drone sightings since mid-November.

“Having closely examined the technical data and tops from concerned citizens, we assess that the sightings to date include a combination of lawful commercial drone, hobbyist drone, and law enforcement drones, as well as manned fixed-wing aircraft, helicopters, and stars mistakenly reported as drones,” reads the statement. “We have not identified anything anomalous and do not assess the activity to present a national security of public safety risk over the civilian airspace in New Jersey or other states in the northeast.”

When “Good Day” hosts asked what he thought the drone might be, Mr. Melham responded by shooting down conspiracy theories.

“I can tell you what it’s not,” he said. “We know for a fact it’s not little green men.”

“And more than likely, it’s not a foreign adversary because they would be able to figure out how to turn off the blinking lights.”