It’s believed the men broke into Preston General Cemetery shortly before 5am on July 30.
Victoria Police said they accessed the commercial mausoleum, and the woman’s casket, by breaking a window.
Officers spoke to the family of the dead woman to try and work out what may have been stolen and why the men would steal it.
Detectives believe it was targeted as no other crypts were damaged and theft seems to be the only motive.
“This is a highly unusual incident and I know there has been a lot of speculation, particularly in criminal circles, as to why this incident happened and who was responsible,” Detective Inspector Graham Banks said.
“While theft is not discounted as the only motive, police are receiving consistent intelligence that this was undertaken as a form of retribution against a relative of the deceased woman.”
He said detectives would investigate with an open mind to try and understand whether the two men “were tasked by another person or group” to commit the casket robbery.
Police have released CCTV of the two men who were wearing gas masks, hooded jumpers and dark clothing.
One had a larger build and one had a smaller build, officers said.