Black marks left on the beach after a weekend festival prompted a resident to ask why a public space was left in such a state.

James McCuthburt was so shocked by the dirt left behind after the On the Beach festival last month that he submitted a freedom of information request to Brighton and Hove City Council to find out how much the clean up cost taxpayers.

After learning that the organiser rather than the council was responsible for clearing any mess, he wrote to councillors, including council leader Bella Sankey, asking them to tell the event organiser to clean the site east of the pier properly.

Mr McCuthburt said: “The filth left on the beach is still very visible and they have not fulfilled their obligations to restore the site to its original condition.

“In previous years it has taken months for rain to wash away the filth left behind and this is unacceptable.

“Not only is this disgusting for beach users but it also creates a horrible impression on visitors which will impact locally owned businesses.

“Like many, I love that we have so many fantastic events in our city but this must not be to the detriment to those using the public space outside of these events.”

Council officials told Mr McCuthburt that the dark markings had been left by “heavy infrastructure” such as the stage – and much of the site had a covering of protective panels.

This is in part because the licensing agreements for public spaces require event organisers to clean up and make good the sites themselves.

Labour councillor Tim Rowkins, the council’s cabinet member for the environment and net zero, said that the council was working with On the Beach to clean up the site.

He said: “The residue left on pebbles following the event is a mixture of mud and dust from the panels used to cover the beach surface.

“We do appreciate this does not look brilliant but it poses no risk to residents or visitors using our beaches. It will wash away fairly quickly with rain and leave no permanent marking.

“We are continually working with organisers to reduce the environmental impact of events and are making significant improvements.

“For example, following our feedback from previous events, On the Beach pioneered sea-safe cups that decompose in the marine environment and utilised battery-supported diesel power, cutting fuel usage by hundreds of litres. The beach clean-up will be at no cost to the council.”

On the Beach was contacted for comment.