The old poker machine gathering dust in the garage, standing pride of place in dad's man cave, or as a decoration in the pool room may set you back more than the cost of a flutter.

Lake Illawarra police have seized nine poker machines from Illawarra homes in the past year, prompting the police licensing division to remind residents that owning, selling or purchasing such a machine is illegal, and carries hefty penalties.

"Even if the machine is dismantled or disabled, operating or not, it is outlawed for a citizen to own one," said Lake Illawarra Licensing Sergeant Gary Keevers.

"It is even illegal to own components, art work or boards from old machines."

Sgt Keevers said the NSW Gaming Machines Act of 2001 effectively outlawed older mechanical machines, and restricted the ownership of newer electronic machines to pubs, clubs and hotels. Offences can carry 12 months imprisonment, an $11,000 fine, or both.

Police monitor online marketplaces including eBay and Gumtree, and attend auctions, to track the sale and purchase of machines.

"The older the machine, the more serious the offence actually is," he said.

Four machines have been seized from Illawarra homes in recent times, which will soon be destroyed by police. Sgt Keevers said police gave notice to owners that it was illegal to own a machine, rather than charging them, as the offence and penalties were not widely known. He said the last charge for such an offence was in 2012, resulting in a $500 fine.

"We issue cautions to those who don't know it is an offence, then seize and destroy the machine." He said those owning a machine could contact Lake Illawarra police's licensing division to have it disposed of.