OAKLAND (CBS SF) – A new surveillance videotape has emerged showing a suspicious individual lurking around an Oakland construction site moments before it went up in flames in May.

In the last year, four suspicious fires have destroyed massive apartment complex construction sites in Oakland. The latest occurred last Friday when a 4-alarm blaze roared through a mixed use complex that include nearly 200 housing units.

A special arson task force of local and federal investigators has been formed and is investigating all four blazes. They have offered a $50,000 reward for any information on the individual or individuals responsible.

KPIX obtained a new surveillance video that captured the moments prior to a large complex being built at 3800 San Pablo Ave. going up in flames during the early morning hours of May 13th.

On the video, a man wearing a hoodie is seen hiding behind a SUV, climbing scaffolding on the building, riding a bike, walking off camera and then coming back into view putting a mask and gloves.

Moments later the fire begins.

The fire at the San Pablo project was the second one at the site in less than a year.

On July 6, 2016, a fire broke out at the construction site where 105 apartments and 25,000 square feet of commercial space were being built.

That fire also burned four adjacent townhouses, an Alameda County deputy fire chief said following the incident.