In the harsh light of day, a caped crusader storms the streets of London to tackle a crime that has long blighted the capital: littering.

“When I said I wanted to save London, I meant it. I will not stop until every single bit of trash is off the streets,” he says in a viral video, narrated in his trademark deep, husky and (suspiciously) American voice, joined by a gang of hooded helpers clearing rubbish-strewn streets in Tower Hamlets.

This was Batman’s first good deed for the capital and, in the month since relocating from Gotham, he has carried out many more: paying parking fines for those visiting loved ones in hospital, giving out “free fuel” to motorists and bringing back £1 chicken and chips to those who once savoured this cheap and filling after-school meal.

But who is he really and what does he stand for?…