CCTV footage has captured a would-be arsonist setting himself on fire while torching a fast food outlet in Melbourne on the early morning of Christmas Day.

The vision shows a pair pouring a flammable liquid over the front of the burger business on Doncaster Road in Doncaster East at 2.40am on December 25.

But as the fire was set, it immediately spread to the clothes of one of the arsonists.

Surveillance footage shows the culprit running down the street with his pants on fire, desperately trying to douse the flames.

The arsonist pulls off his pants and underwear and runs bare-bottomed away from the crime.

The accomplice runs alongside them, but the footage shows them making no effort to help.

Detectives said they ran to a Tarago being used as a getaway car. They believe it was being driven by a third offender.

Police have released the CCTV in the hopes of identifying the offenders.

The fire did not cause substantial damage to the shop, but the sprinklers were activated. A small burn mark was left on the footpath.

Police said the singed pants, shoes and underpants were left at the scene.