Police said the six-foot crocodile barged in through a back door of the crime branch at Nochchiyagama station, 190 kilometres north of Colombo.
"Police men and women evacuated the building when the crocodile crashed in. It stayed put till this morning when wildlife officials showed up and took it away," a police official told AFP. "It did not hurt anyone."
Another official said locals were accustomed to frequent elephant attacks on villages in the remote area, but a invasive crocodile was a rarity.