I've had an experience that links one of my residential smoke detectors activating without any smoke and ASIO so don't be dismissive of such a possibility.

Caller: Detector Inspector

Their call centre uses several phone numbers to berate potential customers until they get people to pay for their service. Once they start, you won't be able to get rid of them.

Caller: Detector Inspector

A dishonest company that pretend to have been booked by the real estates but have not.

Caller: Detector Inspector

Under the guise of a smoke detector inspection company we made an appointment for 5pm because i had work but someone arrived at 8:45am.
Checking the CCTV footage you can clearly see that they waited around the corner for me to leave for work and then they drove up to my house and attempted to gain access into the house from the front and the side of the house.
We forwarded the footage to the police and 2 arrests were made.

I will never again allow some random person onto my property.

Caller: Detector Inspector

Call from Detector Inspector to service the smoke alarm for rental property. Staff answering call is polite and friendly.

is the bed good

detector inspector for smoke alarm maintenance

Annual smoke detector check

Repeated calls saying they are detector inspectors however the number they leave to return the calls is disconnected

Smoke alarm inspector

Smoke alarm inspection service

detector inspector for fire alarms in the home, rental etc

You are not wrong Rossco and when you want to make your own time for them to come they insist on doing the opposite.
she wanted a technician to come at 7am, I kept telling her 2pm is fine anytime after that is fine.
It was like she was too lazy to look through the bookings.
They have cancelled twice now once for the install and once for the malfunctioned smoke detector.

I called back number (03) 9021 6160 reached IVR for a company called Detector Inspector.

They are the Detector Inspector they employ 3rd parties to check smoke alarms in rental properties. My one experience with them is that those they employ are not good at keeping appointments.