Police in Durham region have discovered an arsenal of illegal weapons they believe could have been destined for the black market.

The 67 firearms police seized from a property in Bancroft, Ont. include machine guns, assault rifles, smoke grenades and a 32-inch cannon, along with thousands of rounds of ammunition.

"As police officers, we never want to see this kind of fire power in one place," Insp. Mario Lessard told reporters during a news conference on Tuesday. "It tends to attract attention and could be the target of criminals who want these weapons for their illegal activities."

Police uncovered what was described as "copious amounts of firearms and ammunition," on the morning of March 7, after receiving a tip.

In a joint operation between OPP and the Durham police guns and gang unit, police executed a search warrant on the Bancroft home where they discovered two hidden compartments built into the walls. The weapons were found stored inside.

Police said the stash also included "homemade" assault rifles, and pistols without serial numbers.

"Unfortunately there is a (firearms) market," Lessard said. "The trafficking of firearms has existed for several years and our biggest concern is these weapons going back into the hands of criminals.

"There's no possible reason why anybody would have such an arsenal of weapons," he said.

Police have charged 55-year-old David Alan Kift, a retired RCMP officer, with multiple counts of weapons-related offences.

Lessard said Kift was banned from possessing firearms. He is currently being held in federal custody.

Marion Kift, 53, was also charged with a number of weapons-related offences. She was released following a bail hearing.

Police said they expect to lay more charges as the investigation continues.