Police have confirmed several pills seized in Carleton County last year contained furanyl fentanyl.
The pills were seized near Hartland in September during an investigation into an unrelated matter.
Mounties say the pills are light blue, about one centimetre in diameter, with the words "Percocet 5" written on them.
It's a concern to the RCMP because the pills were labeled as something other than what they are, and they say people who take illegal prescription drugs could be at risk of serious harm.
There's no word yet on possible charges.
A similar pill seized on the Esgenoôpetitj First Nation early last year was later found to contain fentanyl.