Two men overcome by a mystery gas have been discharged from Whangarei Hospital.
The men were affected by fumes at a Carter Holt Harvey catchment pond at Marsden Point shortly after 1pm on Friday and taken to hospital.
Three fire engines and a hazardous materials unit were called to the scene. However, crews could not trace the gas and think it dissipated before they were called.
The incident comes after two Asian crewmen suffocated on a Panamanian-registered logging ship at the port earlier in May.
