Underworld figures disgusted by the death of an innocent woman in a firebombing on the wrong house have been urged to examine their consciences and reveal what they know.

Katie Tangey, 27, was house-sitting for her brother when his home in Melbourne’s west was engulfed in flames early on January 16.

Two men were seen getting out of a car moments before the Truganina house exploded.

They were then spotted fleeing with what appeared to be a jerry can, while Tangey called triple zero from inside. She and the family’s golden retriever died as the three-story townhouse was destroyed.

Police believe it was a targeted attack linked to an ongoing war between criminal gangs over the profits of illegal tobacco.

They say the offenders got the wrong address and Tangey was not involved in the criminality.

An anonymous tipster contacted police and provided the “street name” of one of the men involved, but investigators need more information to follow up, Detective Inspector Chris Murray said on Thursday.

The call revealed someone involved in the illicit tobacco war had a conscience, Murray said, appealing directly to them to help find the two “lowlives” who killed Tangey.

“If they’re disgusted, which they should be, do the right thing, seriously,” he said.

“Call Crime Stoppers; they don’t have to put their name to anything, give us the information we need to progress this.”

Detectives have theories on who was involved but are keeping an open mind, stressing no piece of information is too insignificant.

The appeal coincided with the release of the image of a man who police wanted to speak to over the attack.

The photo was created by compiling enhanced CCTV footage. The man is described as being of Middle Eastern appearance, between 25-30 years old with a slim build and wearing an orange or yellow jumper.

Murray described the incident as one of the most tragic he had seen in 38 years in the force, pointing out that Tangey would have spent her final moments knowing she was about to die.

“Katie was completely innocent, home alone, absolutely in fear and did not deserve this,” he said.

“This is one crime we want to solve, we want to do that for the Tangey family, give them some closure and do what is right for their poor daughter and sister.”

An information caravan with details about the fire has been set up in the local area in the hope of jogging residents’ memories.

-AAP