A wildfire burns in Black Forest, Colo., June 12, 2013. (Credit: Rick Wilking/Reuters)

Was Colorado's most destructive wildfire in history, which burned down nearly 500 homes and left two people dead last June, the work of an arsonist?

Wednesday night, Black Forest Fire Chief Bob Harvey seemed to tip his hat in that direction for the first time, telling ABC affiliate KRDO that the Black Forest Fire was "human caused and appears intentional." Investigators had previously said the fire had been "human caused," but said that didn't necessarily mean arson.

Harvey's comments have drawn fire from El Paso County Sheriff Terry Maketa, who blasted the fire chief in a harsh, middle-of-the-night news release.

"Do not buy into Chief Harvey's claims until it's confirmed by the actual agency that has been the lead in the investigation and will base its findings on indisputable scientific evidence that can withstand the scrutiny of the criminal justice system. Right now, that isn't the case," Maketa said.

Maketa said Harvey "may be merely covering his own mishandling of this event in an attempt to avoid responsibility for allowing the fire to get out of hand.

"Furthermore, this chief didn't even know homes were burning at a time several were engulfed and never even requested evacuations of nearby households as the fire rapidly grew out of control, clearly placing citizen's safety in jeopardy. It's an injustice that he has chosen to jump to these unjustified and inconclusive assumptions without any effort to coordinate with local investigative authorities that have expended extensive resources to identify the cause and manner of this serious tragedy," Maketa said.

Reached by phone Thursday morning, Harvey stood by his comments of the night before that the fire had been intentionally set, a conclusion he said his own team of investigators came to.

"We reached that conclusion based on evidence, observations and statements," Harvey told ABC News.

Harvey said he was "not surprised" by the sheriff's comments but declined to elaborate, saying he was not aware of any rift between him and the sheriff - until now. But he seemed to acknowledge that the two agencies hadn't been fully cooperating with each other.

"If there is an ongoing investigation, I'm not aware of it because they haven't informed us," said Harvey, a 40-year fire department veteran.

Harvey said investigators had not identified any suspects.

Maketa has never been exactly shy in taking swipes at various public officials in the past. In March, he accused Democrats in the Colorado legislature of extortion, claiming they had threatened to withhold state funding to county departments led by sheriffs who opposed the gun control measures being debated at the time.