Organisers of a topless motorbike parade in the New Zealand city of Christchurch hope to take their stunt to Australia.

The so-called Boobs on Bikes parade was held to promote an erotica expo and a group of about 20 motorcyclists - a mixture of men and women - took off their tops while they rode through the South Island city.

Organiser Steve Crow said Boobs on Bikes was an exercise in equal rights and was allowed after a test case he brought in 2005 that determined women could appear topless in public.