A self-confessed “grammar vigilante” has been secretly correcting bad punctuation on street signs and shop fronts in Bristol for more than a decade.

The anonymous crusader carries out his work in the dead of night using the “Apostrophiser” - a long-handled tool he created to reach the highest signs.

The man, who wishes to remain anonymous, told the BBC that correcting rogue apostrophes is his speciality.

He uses stickers, rather than paint, to cover up errors.

“I do think it is a cause worth pursuing. I have felt extremely nervous and the heart has been thumping,” he told the BBC.

But the man maintained that he had not committed any crime.

“It’s more a of a crime to have the apostrophes wrong in the first place,” he said.

PA