A runaway pig has caused havoc in the sleepy West Australian town of Denmark, disrupting traffic during a two-kilometre romp through the main streets.

The 60-kilogram black porker was first spotted lurking on grass outside the local police station on Thursday morning, having apparently escaped from a nearby property.

Residents chased the young pig through the streets, past a car wash and church, before it was eventually cornered outside a pizza shop.

It took five people to hold the pig down so it could be tied up.

Denmark business owner Annette Stock said it was quite a sight to see the animal happily trotting the wrong way down the town's main street.

"I went to my shop and told my staff I was going to go back and catch it," she said.

"I did a few bog laps around and was told that it was heading back down the hill through the centre of town.

The pig is being held in the local pound while rangers try to find its owner. ( Supplied: Denmark Police )

"It was going down the middle of South Coast Highway on the wrong side of the road.

"We followed it around the corner on to Strickland Street and managed to catch it in front of the pizza shop."

Ms Stock said she was amused to see a sign in the shop's window advertising 'free range meats available' on the pizzas.

She said the pig's adventure lasted for at least half an hour and spanned about two kilometres.

"It certainly was putting a lot of a fight and squealing her head off, making a lot of noise, so it was quite entertaining."

Another resident, who did not want to be identified, said traffic was held up on South Coast Highway and drivers were honking their horns, trying to get the pig to move off the street.

Shire of Denmark's community and regulatory director Greg Harwood said it took three people to hold the pig down before rangers arrived.

"It was a reasonably big porker and they actually had to hogtie it in the end, believe it or not, and now we've got it in our pound," he said.

"I think he was just out for a walk.

"Really we're just waiting for the owner to step forward now so we can re-unite them with the pig."