"The first time I heard it I thought it was a swarm of bees, as I am a beekeeper.
"Then I saw it was a drone, right outside my window as I was getting dressed for bed."
He said it had been targeting single woman living in the area too.
"Apart from privacy and it being a bit creepy, my other concern is that it could have been casing places for a burglary."
Keenan said he later found footprints on his property in freshly dug soil.
The sightings come after the Herald reported that a drone had spied on a mother and daughter sunbathing in Mt Wellington, and hovered above other properties in the area.
Keenan said he phoned the police about the incident, who referred him to the Civil Aviation Authority (CAA).
"The CAA asked me to record the registration number if I see it again. But there is no way I would be able to read that from a distance.
"They then referred me back to the police.
"They just seem to be palming it off. Nobody wants to deal with it.
"I said to the policewoman on the phone I would shoot the drone if I saw it again.
"Then she turned it back on me and said I would be then liable for destroying private property."
Morgaine Halligan and her mother Melissa Rays had been sunbathing in Rays' private Mt Wellington backyard when they saw a drone hovering over them.
"It is just creepy, as you don't know what the purpose may be," Halligan told the Herald.
A neighbour had reported that incident to police, but was referred to the CAA too, she said.
Flying a drone over people on private property without consent is prohibited in part 101 of the Civil Aviation Act.
Recording people with a drone on their property is also a breach of the Privacy Act, and recording someone getting changed or sunbathing is a breach of the Crimes Act.
Privacy Commission senior communications adviser Charles Mabbett said people could make complaints to them in such circumstances, however identifying the perpetrator was difficult.
"For us to investigate, we would need to know who is being complained about. And this is a difficulty with drones. How can people identify a drone operator who is often out of sight?"
Privacy Commissioner John Edwards said they were seeing an increase in concern about drones.
They have been distributing material with police and the CAA to retailers when they sell drones, so operators can see the minimum expectations of them.
"The top line on that material we have produced says 'don't be creepy'," Edwards said.
Read more: Hundreds of drone reports in five years: Privacy Commissioner says 'don't be creepy'
A CAA spokeswoman said they had received a total of 718 reported incidents involving drones, otherwise known as unmanned aerial vehicles (UAVs), since 2013.
From those reports, 192 were reported complaints of UAVs being flown over people's properties without consent.
The spokeswoman said when it finds rules have been breached, the CAA takes appropriate action - which could be a warning, a fine or prosecution.
Penalties for an individual flying over people or property without their consent range from $500 to $2500.
The spokeswoman said if someone believes a drone is breaching Civil Aviation Rules they should try to get as much information as possible about the drone and operator and report it to the CAA.
If they consider the drone is being flown with criminal intent, they should contact police immediately.
A police spokesman said they could not comment on the incidents as no official complaints were made.
He said the CAA is the enforcement agency who will investigate if there is deemed to be a safety risk to persons, property or other aircraft.
However, if people believe a drone has been used as part of a criminal offence, then they should contact police.
