Overseas backpackers and itinerant workers are heading to Lismore to squat in flood-affected houses.

The properties involved are among 623 purchased by the New South Wales government's Reconstruction Authority as part of the buyback program introduced after the devastating floods of 2022.

The ABC has been told the people learned homes in the area were vacant via a loose social network formed at Tasmania's Rainbow Gathering festival in March.

Katherine Hull from the UK, who is in Australia on a working-holiday visa, is among the squatters occupying a house on Pine Street, North Lismore.

"In Tasmania I met some lovely family at the Rainbow Gathering … and we all kind of spread across Australia, did our separate things and ended up in the Northern Rivers," she said.

Ms Hull said she wanted others to have the same opportunity.

"I think it is a priority that these houses should be lived in, looked after, brought to life," she said.

'Ghost town' needs to be filled

New Yorker Emma O'Shea, also in Australia on a working holiday visa, is living in the same house, which she heard about through Rainbow Gathering connections.

"There's different groups and chats you can get into, whether it's WhatsApp or Facebook — it's like a community network," she said.

"That's the idea of [Rainbow Gatherings], to kind of create spaces to take care of each other and make sure that everyone has the basic necessities."

Lismore local Dylan McConville, a supporter of the Pine Street squatters, said the international flavour of the group was a welcome addition to the community.

"It means bringing new people, new culture, new different arts, new, different ideas and vibrancy to a community that's been really suffering in the last year," he said.

About half of the 20 people at a protest organised by community group Reclaim Our Recovery were from overseas, six of whom said they were living in two neighbouring houses in Pine Street in North Lismore.

The NSW Reconstruction Authority said it had identified four properties in Pine and Bailey Streets that were being occupied by squatters who were not the original residents.

'Homelessness' of buyback system

The Resilient Homes buyback program is one of the most visible changes to Lismore since the 2022 floods.

It has seen the city become littered with fenced-off, boarded-up houses awaiting demolition or relocation.

Lismore Mayor Steve Krieg said there was a reason the homes were unoccupied.

"That's because they've been bought back by the government to hopefully relocate them to new sites or, for the structurally unsound houses, to actually demolish them," he said.

But Reclaiming Our Recovery has supported the occupants at Pine Street because of a fear that many of the timber homes affected by the floods will be destroyed.

"There's plenty of locals who are experiencing the homelessness of the buyback system," said Reclaiming Our Recovery spokesperson Andrew George.

"It's for them that this is advocating and drawing attention to an issue that needs to be remedied."

NSW Reconstruction Authority (RA) said in a statement to the ABC that those squatting in the homes had been offered alternative accommodation.

"The RA has been working with Homes NSW and the NSW Police force with a view to having the persons leave those houses voluntarily," a spokesperson said.