The incident took place near to Whitehall Lane at around 9pm on Saturday (July 12), when firefighters were called to reports of grass alight in the area.
In the video, the officer can be seen attempting to extinguish the flames as smoke rises into the air.
A person is also seen running past in the background during the incident.
The London Fire Brigade said it received eight calls about the fire, which was brought under control by 9.23pm.
One fire engine from Plumstead Fire Station attended the scene.
A spokesperson for the London Fire Brigade said: “Firefighters were called to grass alight near to Whitehall Lane in Erith on Saturday.
“The Brigade’s Control Officers received the first of 8 calls to the fire at 2100 and the fire was under control by 2123.
“One fire engine from Plumstead Fire Station attended the scene.”
