Jacko the Jack Russell trapped in Kaikoura quake crack

The owners of a three-year-old dog are desperately trying to free him from a five metre-deep Kaikoura earthquake crevice.

Jacko the Jack Russell's been stuck in there since Thursday morning when he and his owner, Shane Sitruc, were possum hunting in the White Cliffs area of Inangahua on the South Island's West Coast.

Mr Sitruc's partner, Willow Leigh, says Jacko was chasing a possum when he lost his footing.

"He didn't realise it was a straight drop off until it was too late. He just couldn't stop."

They tried using shovels and calling him out but soon realised the worst - Jacko looked to be stuck about five metres below ground.

"As soon as we shone a torch down we saw there was no way he'd be able to walk out on his own. It was just too steep."

Ms Leigh says a lot of new cracks have opened up in the area since the Kaikoura earthquake, and she believes this is one of them.

The pair have stayed at Jacko's side since yesterday morning, calling in a digger to help in the rescue.

"We worked right through the night and we're not going to stop until we get him out," Ms Leigh says.

"We're pretty tired and exhausted but he's family and we can't walk away from him."

Ms Leigh says they're trying to stay positive, but Jacko's starting to lose his bark.

"He was yelping all night, [like he was] saying 'help me' non stop. I just don't know if we'll be able to help him."

Newshub.