The 50cm-long golden-crowned snake was released to bushland at the top of the escarpment Monday afternoon, having enjoyed the sensation of local government carpet on its belly since at least Friday morning.

A cleaner spotted the creature in the foyer then, prompting Wollongong council to place the library in lockdown. 

Matt Neill, facilities operations manager, was among the staffers who joined a “very thorough” search for the scaly intruder.

“I checked the CCTV, but because it was so little it didn’t show up,” he told the Mercury.

It wasn’t until Monday morning that the forest specialist was spotted again, heading west down the corridor. 

Mr Neill used an empty cardboard box to trap it, then weighted it down with books until professional snake catcher Jo Matthews arrived. 

“When presented with a snake bag it pretty much hooked straight in there,” Mr Matthews said.

“It had been a warm day so it was fairly lively. There were only a little bit of theatrics really then it settled down.” 

Golden-crowned snakes are nocturnal and secretive. They use scent to locate sleeping lizards, then eat them.