A planned 91-storey skyscraper on Albert Street in the Brisbane CBD has hit a problem, with its earthworks predicted to hit the Cross River Rail underground tunnel zone.

The approved 30 Albert Street tower, four metres taller than the near-completed 270-metre Skytower next door, is being developed by Singapore-based luxury property group World Class Land.

The 2016 development application, approved by Brisbane City Council, would see a skyscraper as tall as Skytower rise up over the city.

It could be the second maximum-height tower in the city, reaching 274 metres tall, after The One Residences at 300 George Street, which is still under construction.

Any taller would be in conflict with aviation height regulations.