A huge mural has been stolen from outside an Auckland train station, less than a day after it was put up by City Rail Link staff.

The mural depicting a train-waka hybrid was put up on Galway street yesterday, but was gone by Friday morning.

City Rail Link spokesperson Carol Greensmith said the thieves went to a huge effort to steal the piece.

"[It] would have been jolly heavy because it's 10 metres long and over a metre high and it's very heavy duty PVC."

Greensmith said they've looked over CCTV footage, and discovered the culprits took the work at 4am yesterday.