United Utilities have enlisted the assistance of a mysterious “sewer monster” in a bid to encourage people to think twice before flushing detritus such as baby wipes and cotton buds down the loo.

A series of probes were lowered into actual sewers by the North West water company to record grainy images of blocked drains, inadvertently capturing some shy and fleet footed denizens in the process.

Some 15,000 blockages occur each year as a result of nappies and other unwelcome items, leading to blow backs of effluent onto streets and even homes.

The campaign runs with the tagline, “what gets flushed may come back to haunt you.”