Police have confirmed the grenade was handed in voluntarily. No arrests have been made and the incident isn't being treated as suspicious.
A police operation is underway after a man entered Cessnock Station with what appeared to be a hand grenade.
Staff had to be evacuated with an exclusion zone put in place around the Maitland Road building after the incident began at around 3pm.
Defence Force Personnel are on their way to remove the item.
We're being asked to avoid the area.