A bomb disposal team were called to an address in Billingham after an item which looked like a grenade was discovered.
The bomb disposal experts and Cleveland Police were called to Haverton Hill Road at around 2.45pm today, Friday, January 5, following the discovery.
Police officers put a cordon in place whilst colleagues from the bomb disposal team assessed the item.
Roads remained open during the investigation, but members of the public were advised to only travel past if necessary.
A Cleveland Police spokesman said: "Police received a report that an object which looks like a grenade was found on Haverton Hill Road at around 2.45pm today.
"Officers are currently at the scene and have put a cordon in place whilst colleagues from the bomb disposal team attend to assess the item."