Hunt on for missing WWI machine gun

Thieves have made off with a machine gun that has been on display in a NSW country town for 90 years, police say.

And although authorities have been advised that it's "highly likely" the gun does not work anymore, they can't say for sure.

Residents in the town of Wallendbeen, near Cootamundra, noticed the German Maxim missing from the local memorial hall earlier this week.

"We've been advised the gun was seized in Belgium in October 1917 during World War I, and was presented to the local community five years later," Cootamundra Local Area Command's Inspector Frank Brown said on Thursday.

He said the weapon was mounted on a wall 10 metres from the ground, so it would have been difficult to remove.

"Due to the circumstances and lapse of time since its donation in 1922, police are unable to confirm that the weapon was no longer functional; however, advice received indicates that this is highly likely," Insp Brown said.