In a video posted to TikTok by @mcoldkentroad, the grim footage captured by a worker there shows earthworms in the drain of the branch's drink station.
“This is McDonald’s Old Kent Road in South London,” a voice over in the video said.
While the TikTok user captioned the video “maggots” McDonald’s did not help matters by confirming they were actually earthworms.
In a statement to MyLondon, a spokesperson for the fast food restaurant chain said: "We take cleanliness and hygiene extremely seriously. Unfortunately, a number of weeks ago we were made aware of an issue in the drain serving the drinks station at our Old Kent Road restaurant.
"We immediately closed the drinks station and our hygiene team identified the cause of the issue which was fixed before a deep clean was carried out.
"The area was inspected by external specialists and no drinks were served to customers until we were sure that the issue was fully resolved.”
It comes just a week after maggots were filmed raining down on customers at another London McDonalds branch in Beckton.
Images from the incident showed live maggots allegedly falling into a customer’s meal as the larva were seen "all over the floors".
It has been reported that one person filming the incident was heard saying: "This guy is trying to stop me from taking pictures."
A second person behind the camera added: "Everywhere, and they're moving."
As the camera person zooms in on the floor, larva are shown wriggling around tables and the floor “they're alive,” one person exclaimed with another witness claiming that they “came from the roof".
A McDonald's spokesperson said of the horrible incident: "Unfortunately, an incident occurred today at our restaurant in Beckton and we would like to apologise to any customers who were impacted.
"The restaurant was immediately closed, and a thorough investigation has found the root cause which has now been resolved.
“The restaurant remained closed throughout the day for the investigation and we brought in external specialists to carry out a deep clean.
"We have worked closely with our pest prevention company during this process.”
Prior to this, an mice infestation led to the closure of yet another McDonalds London branch.
Health inspectors found rodents and hundreds of droppings at the Leytonston restaurant, with customers asked to leave upon the discovery.
A dead mouse in a storage cupboard was found during the inspection which was prompted when a customer made a complaint.
The branch was closed down and cannot reopen until it is "completely a rodent and risk-free zone".