A plane known to be an RCMP-registered surveillance aircraft has been flying laps over the Greater Toronto Area all week.

This mysterious flight is not part of the ongoing practice runs for the 2023 Canadian International Air Show, and if the aircraft's past activities are any indication, it may instead be taking part in some sort of secretive surveillance operation above the city.

X (formerly Twitter) user @matttomic was among the plane watchers who spotted the aircraft on radar, noting its odd looping path over Brampton, Toronto, and Markham.

An RCMP-owned surveillance plane, C-GMPB, is now on its 10th straight tight circular loop around the 404 & 407 area in north Toronto/Markham, after doing four loops around Brampton pic.twitter.com/9ZeSH8GCo9

— ℳatt (@matttomic) August 31, 2023

Attempts to monitor the plane via popular tracking services like FlightRadar24 are blocked at the request of the plane's owner — the Royal Canadian Mounted Police — however, the plane's movements can still be tracked via another service, which shows that the aircraft continued its looping path around the GTA for quite some time.

Similar patterns have been spotted throughout the week.

It's been doing similar patterns all week. On Tuesday it took off from London and did the same circling around Brampton, then Markham, followed by 9 loops of the Toronto harbour, before heading back.

Similar on Tuesday, just with an added detour up by Wasaga Beach. pic.twitter.com/XkU3i4cL5K

— ℳatt (@matttomic) August 31, 2023

The aircraft was last seen on approach to London International Airport (the Ontario one) on Thursday afternoon.

So, what's the deal with the mystery plane?

Other X users have noted the aircraft on similar flight paths over various parts of the province in recent months. Such flights have confused locals for years, including one case in 2019 where the aircraft turned out to be pursuing a suspected terrorist above Kingston.

The same plane circled Kingston for days and confused residents in 2019 in what turned out to be surveillance of a suspected terrorist https://t.co/HqTadBpNMO pic.twitter.com/wnYdpD41M6

— ℳatt (@matttomic) August 31, 2023

Following an arrest in what was described as a "national security investigation," officials confirmed that the RCMP utilized their Pilatus PC-12 surveillance aircraft in the course of the search for the suspect.

The Pilatus PC-12 single-engine turboprop seen above Toronto this week is just one of 16 operated by the RCMP, and the only specialized "Spectre" model used by the force in Ontario.

The plane's Swiss manufacturer, Pilatus Aircraft, describes the Spectre model as "virtually undetectable" by persons under surveillance.

But apparently, very detectable by people with access to flight radar.