The man who tied up a woman and held her at gunpoint at a lost dogs home in Melbourne’s outer south-east seemed to believe animals were being killed at the shelter.

The 23-year-old animal ranger parked her vehicle in the carpark of The Lost Dogs animal shelter on Thompsons Road, Cranbourne West, when she was confronted by an armed gunman wearing military-style clothes about 10.20pm.

Detective Senior Sergeant Glen Cruse from the Casey Crime Investigation Unit said the woman winded down the window of her vehicle after noticing the man dressed in camouflage gear, who she believed may have been a police officer at the time.