The huge reptile, which weighs in at at a whopping 63 stone, was discovered by the workers after they carried out a controlled explosion in the Cave of Altamira in the northern state of Para.
Video footage taken by one of the crew pans down the snake's enormous body - which measures one metre in diameter. After making the frightening discovery, the workers chained the animal to a crane and later lifted it up to reveal its yellow spotted under belly - a move which was criticised in the comments when the clip was uploaded to YouTube.
It's claimed the builders killed the snake rather than leave it in its natural habitat but this has not been confirmed.
WATCH FULL VIDEO BELOW
DOWNLOAD FULL VIDEO BELOW
