The last remaining prime piece of undeveloped Byron Bay beachfront commercial real estate goes under the hammer early next month.

The 618 square metre block on the corner of Jonson and Bay Streets is occupied by an older-style, two-storey building containing four flats, with industry observers expecting it to sell for around the $5 million mark.

Once owned by John Cornell and his wife Delvene, the site is now owned by the van Handel family who own The Beach Hotel across the road.

There is Byron Council development approval for the redevelopment of the site comprising two units and a large ground-floor shop.

The property will be auctioned by Byron Bay First National Real Estate on Friday, December 2.

Agency principal Chris Hanley said there had been a lot of interest in the site from around the country.