The Queensland government is trying to lure casino money to help fund its $5 billion tunnel.

One of several options tabled to drum up extra funding is for the construction of a train station 35 metres below the site of a new casino in the middle of the city.

Draft plans reportedly show a train station sitting below a seven-story underground car park, both underneath the corner of George and Alice streets.

Transport and Main Roads Minister Scott Emerson said the station-casino collocation proposal was being considered.

While both the station and casino are still in very early stages, the gambling hub at least seems all but set in stone. Two large firms; Echo Entertainment and James Packer's Crown Resorts, have made it known that they are interested in the site at 100 George St. Queensland Premier Campbell Newman has confirmed he wants the state’s latest casino to be built there.

Plans are taking shape for the whole of the multi-billion dollar tunnel project, which seeks to ease congestion and creating new commuter options for Brisbane’s CBD with the construction of a large tunnel that will carry both buses and trains on split levels.

A significant amount of private investment will be needed to pull the project off, so it is understood a range of options will be considered to get non-government money involved.

On the technical side, the dual-use tunnel will be dug with an interesting boring machine – with the ability to dig tunnels 15 metres in diameter it will be one of the largest ever employed in the southern hemisphere.

More information on the first industry briefing coming up on the 10th of December is available here.