Banksy has struck again – but a council in the east of England has struck back, removing his artwork that it said contained “offensive and racist remarks”.

The latest mural by the controversial graffiti artist, whose real identity is not widely publicised, was painted overnight in Clacton-on-Sea, in Essex, a week ahead of a byelection in the town triggered by the decision of local Conservative MP, Douglas Carswell, to defect to the UK Independence Party (Ukip).

The work showed five grey pigeons holding up signs including one stating “go back to Africa” towards a more colourful migratory swallow. One of the pigeons’ signs read “migrants not welcome”, while another held a placard that read “keep off our worms”. Ukip argues that Britain’s immigration policies are too lax.

Nigel Brown, communications manager for Tendring district council, said it had received a complaint on Tuesday that “offensive and racist remarks” had been painted on a seafront building.

“The site was inspected by staff who agreed that it could be seen as offensive and it was removed this morning in line with our policy to remove this type of material within 48 hours,” he said.

“We would obviously welcome an appropriate Banksy original on any of our seafronts and would be delighted if he returned in the future.”

It has been suggested that the council did not realise that Banksy was responsible for the work before scrubbing it off the wall. Other pieces he has painted have been valued in six figures.

A spokesman for the artist said he would not be commenting on the council’s actions.

The Clacton mural had been the second piece of art created by Banksy this week. On Tuesday a piece called Art Buff appeared on a wall in Folkestone, Kent – another part of Britain where immigration is high on the political agenda.

That work has been protected by a clear plastic sheet and the owner of the building on which it was painted has employed a security guard.

Banksy confirmed that he was responsible for the Folkestone art on his website. However, Tendring council removed the art before he had announced it online.

Last week a Banksy artwork that disappeared from a building wall went on display once more after being hidden under a bed for four years.

Leopard and Barcode, one of the artist’s celebrated early stencil works, had been situated on the side of a house on Pembroke Road, Bristol. It went missing from the property in August 2010, during extensive building work, and its location remained a mystery.

However, it could be seen once more at Nailsea school in Somerset at an open evening after being brought to the secondary by an unnamed teacher, who had kept it under her bed wrapped in a blanket since 2010.

It was taken off the wall in Clifton by the teacher’s husband, an architect, after the owner of the property wanted to demolish it and rebuild.