Police are on the hunt for three girls, who appear to be teenagers, after releasing CCTV of a suspicious fire earlier this month.

Investigators believe the blaze was deliberately lit to grass under the Roslyn Park Drive overpass, Melton West, about just before 9pm on January 3.

No one was injured and no property damaged but the grass fire spread rapidly along creek before being extinguished by CFA crews.

In footage of the incident, the three girls watch a car go past before one girl jumps over the concrete fence into the long grass.

She jumps back over and they begin running away, before going back and looking at the site.

Once seeing the flames, they set off along the bike path near the creek.

Anyone who recognises the youths or who may have information in relation to the incident is urged to contact Crime Stoppers on 1800 333 000.