Engineers working on sewers in Gloucestershire have removed an “unusual” blockage after a duck was found roaming the underground pipes.

The lone duck, believed to have been searching for algae to eat, was safely extracted after she was seen waddling along inside a pipe which carries rainwater underground.

The waterfowl-clogged conduit near Frenchay near Bristol was inspected by the Environment and Flooding Protection team at Wessex Water after they sent a robotic camera into the underground sewer system.

The camera captured the moment the duck stopped in its tracks and approached the lens with a quizzical look.

The duck then turned away from the camera before wandering back through the pipe.

It is understood that the duck managed to enter the underground sewer through a nearby access point. The animal was unscathed and safely removed from the conduit by engineers.

Though work to unblock sewers is common, engineers at Wessex Water have described this incident as “more unusual” than their other jobs.

A Wessex Water spokesperson said: “Our survey teams have come across a variety of blockages when regularly inspecting our foul and rainwater sewers – but this was one of the more unusual ones.

“It’s often masses of wet wipes that are discovered, which cause blockages that can put homes and the environment at risk of pollution.

“In this case, however, it was more of a moving impediment and, thankfully, our team were able to help the duck back above ground safely and none the worse for her escapade.”