Federal and city authorities investigating an arson of townhouses under construction in Point Breeze this month are searching for a man seen walking on surveillance video apparently about a block from the site on the night of the blaze.

Meanwhile, Ori Feibush, the real estate developer overseeing the damaged project, said Monday that he would contribute $90,000 to a reward for information leading to an arrest and conviction in the case, boosting the total potential payout to more than $100,000.

"It is an incredibly serious crime that, if not for an incredibly diligent and large group of firefighters, would have resulted in absolute catastrophe in the neighborhood," Feibush said.

The video, released by Philadelphia police and the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), appears to show a thin white man wearing a dark hoodie, brown shoes, and a backpack. An ATF spokeswoman said the video was shot on the 1900 block of Reed Street.

Police said the video was recorded before the fire but did not specify what time. A short time after the man walks west on Reed, the video appears to show, he can be seen walking east on the same block, this time without the hoodie.

Philadelphia police described the man as a "person of interest" in the case. Fire Commissioner Adam Thiel said last week that investigators were working around the clock to identify anyone involved, but he declined to offer details.

"We're really confident our fire marshals and partners with [police] will find out who is responsible and bring them to justice," he said. "I am really confident about that."

The two-alarm fire, which was reported around 4:15 a.m. May 1, destroyed four large townhouses under construction and damaged five others at 20th and Wharton Streets. It took about 75 firefighters an hour to bring the fire under control.

The townhouses, each expected to be valued at more than $500,000, were being constructed by Feibush. Feibush has sparked controversy in the past, accused of gentrifying parts of Point Breeze at the expense of long-term residents. He and his company, OCF Realty, have been targeted with vandalism and harassment. Fliers criticizing his company were posted in the neighborhood just weeks before the fire.

Feibush said Monday that construction at the site had begun again, and that it was "truly a miracle" that no one had been injured or worse during the blaze.

"This is a situation that thankfully didn't kill anyone," Feibush said. "Someone with such reckless disregard of the lives of their neighbors is truly somebody that should be apprehended."

At least $102,500 in reward money is available for information leading to an arrest and conviction in the case: The ATF is offering $10,000, and Councilman Kenyatta Johnson's office has offered $2,500.

Anyone with information can reach the ATF at 1-888-283-3473 or atftips@atf.gov, or Philadelphia police at 215-686-TIPS. Tipsters can also send information via text to 773847.

Staff writer Stephanie Farr contributed to this article.