A video has emerged from London, UK, of a barista at a coffee chain refusing to sell food to a customer who was intending to give it to a homeless man.

In the footage, captured on July 18 at Costa, Waterloo Station, the barista tells filmer Adrian Pinsent they can't serve him, telling him that they would be prosecuted by police.

''He wouldn't sell me the food as he said the police will prosecute Costa for it,'' the filmer wrote online.

''The guy was with me and chose the food, and I was refused the purchase even when I said it was for me.''

''This argument went on for five minutes and I only stopped because I would have missed the last train home. It's a f***ing disgrace and bulls*** as well,'' he added.

A spokesperson for Costa said, “We can confirm we do not have a policy that restricts customers purchasing food for anyone who is homeless. We believe the store was given misinformation, which has now been corrected.”

Costa barista refuses to sell me food for a homeless person.