Concern about a dangerous chemical that's been found in illicit drugs here

Twelve people have been hospitalised because of powdered fentanyl that's been found in products sold as cocaine and methamphetamine in the Wairarapa area.

The National Drug Intelligence Bureau's Detective Inspector Blair MacDonald says it's incredibly difficult to track how much of the chemical is in the country.

He says white powders should be treated with extra suspicion.

MacDonald says those who have bought powder being sold as cocaine should get it checked.