A stolen memorial dedicated to a young man who died in Victoria's Black Saturday's bushfires, has been returned to his family.

The sculpture was taken from Carol and David Matthews' Diamond Creek home, north east of Melbourne, last week, leaving a space in their garden they had dedicated to their son Sam.

After Ms Matthews spoke about the theft on 774 ABC Melbourne last week, there was an outpouring of support on the station's Facebook page, and a photo of the stolen sculpture was widely shared.

At the weekend, the sculpture was found dumped at the Greensborough war memorial, and later returned safety to the Matthews' home.

"We were just jumping up and down," Mrs Matthews said.

"We were so down in the dumps and depressed, and getting it back was almost like this artificial high."

Ms Matthews said the ordeal gave her and her husband a realisation of how many people cared about their loss.

"Even if we didn't get it back, just reading all the comments from people (on the ABC and Victoria Police Facebook pages) restored my faith in people, that they are good," she said.

Unfortunately for the police officer returning the sculpture, it had become so widely recognised onlookers were suspicious when they saw it in the back of his car.

"The policeman was in plain clothes in his own car, and as he was driving, he was getting all these filthy looks because he had the sculpture in the back and people started taking photos and recording the registration," Mrs Matthews said.

"At one stage he had to pull over and take a call and he got bailed up by someone saying 'is this yours? Do you have proof?'"

"In the end he had to show his badge and say hey 'I'm one of the good guys, I'm taking it back'."

Sam Matthews died in the 2009 bushfires, and with almost all photographic memories of him also being lost to the fires, the sculpture is their strongest reminder of their son.

"Getting it back really did give us a boost - we put it straight back where it was meant to be, and neighbours walking past have been cheering now."