The message has been painted across the pavement of Ladywood Road in Oakwood, next to a paving stone which has been dislodged.
The message reads, "NPT CCTV. We are watching."
NPT stands for Neighbourhood Policing Team, although it is not yet clear whether the Leeds North East NPT are behind the message.
Yorkshire stone can fetch as much as £50 to £85 per square yard, which has made it a target of thieves in recent years.
In 2016, several stones across Leeds were sprayed with unique ID tags which are invisible under normal light.
This means that stolen flagstones can be traced by police and those handling or selling them can potentially be prosecuted for theft or handling stolen goods.