An air-to-air missile "in perfect working order" has been seized by anti-terrorism police in northern Italy, along with a huge stash of automatic weapons, ammunition and material featuring Nazi symbols.

Key points: Police said the French-made air-to-air missile appeared to have once belonged to Qatar

Police said the French-made air-to-air missile appeared to have once belonged to Qatar The suspects had tried to sell the missile on WhatsApp

The suspects had tried to sell the missile on WhatsApp 26 guns, 20 bayonets, 306 gun parts and more than 800 bullets were also seized

Three men were detained in the raids that targeted a number of properties, including one linked to a neo-fascist Italian political party.

The early morning raids followed a year-long anti-terrorism investigation into Italian far-right groups who fought in eastern Ukraine, local media said.

In a statement issued on Monday, Turin police said one of the men arrested was a customs officer who had previously stood for parliament for the neo-fascist Forza Nuova party.

At his home in Gallarate, police found nine assault weapons and nearly 30 hunting rifles, pistols and bayonets, as well as ammunition and antique Nazi plaques featuring swastikas.

"The police investigation ... came into being because of the activities of some Italian fighters with extremist backgrounds who had taken part in the armed conflict in the Ukrainian region of Donbass against the separatists," the police statement said.

Weapons from Austria, Germany and US

Police detained three men, including one tied to a neo-fascist Italian political party. ( AFP: Polizia di Stato )

Two other men were detained after police found a French-made Matra missile at an airport hangar that appeared to have once belonged to the Qatar armed forces.

"During the operation, an air-to-air missile in perfect working order and used by the Qatari army was seized," the police statement said.

Police said the suspects had tried to sell the missile in conversations with contacts on the WhatsApp messaging network.

Among other weapons uncovered were 26 guns, 20 bayonets, 306 gun parts — including silencers and rifle scopes — and more than 800 bullets of various calibres.

The arms were primarily from Austria, Germany and the United States.

At least 30 Italians have joined the fight on both sides of the conflict in eastern Ukraine.

Early this month, three men were found guilty by a Genoa court of fighting alongside the Russian-backed separatists who control a large swathe of Ukraine's Donetsk and Luhansk regions.

More than 10,000 people have been killed since 2014 in fighting between pro-Russian separatists and Ukrainian forces in eastern Ukraine.

Skirmishes with Ukrainian government troops continue, but the frontline has remained static for more than a year.

ABC/wires