BUFFALO, N.Y. -- A smuggling operation used drones to fly drugs across the Niagara River from Canada into upstate New York, using a newly purchased US$630,000 house along the river as a drop point, according to a criminal complaint unsealed this week.

One person has pleaded guilty and two others face charges after an investigation that started in September 2022. U.S. Border Patrol agents tracked a drone through an overnight excursion from an upscale neighborhood on the U.S. side of the border to the vicinity of an Ontario winery and back.

On the return trip to the house in Youngstown, New York, a package hung from the drone's chassis, according to a court filing. Law enforcement officers were in place as the drone hovered in the backyard before landing near the suspects.

The package was found to contain about 6 1/2 pounds (3 kg) of the drug MDMA, commonly known as ecstasy, investigators said.

A search of the house turned up numerous drones and controllers but almost no furniture except for mattresses on the floor, the complaint said.

Data from the drones indicated there had been five cross-border flights prior to the September 2022 flight. The first occurred in May 2022, a month after the home was purchased in the name of one of the suspect's relatives, the filing showed. The Niagara River is around 1,800 feet wide (550 meters) in Youngstown.

Two of the suspects, from New York City and California, are believed to have made short trips to Buffalo for the drone flights, the complaint said.

The New York City resident appeared in U.S. District Court in Buffalo on Wednesday on drug and conspiracy charges. He was released on bond.

Another suspect pleaded guilty in February.