A woman claims she was told by McDonald's staff she could not buy a homeless man a meal "in case he became aggressive".
Frances Burscough noticed the man on the street near the Walton Road branch, in Kirkdale, Merseyside, to buy a coffee on her way home on Monday, December 28.
She says she was "lost for words, except to say 'he’s a human being not a f****** herring gull" when she asked if she could put the food on her order for the man, Liverpool Echo reports.
McDonald's has since said that it does not have any policy in place to prevent people buying food for the homeless and said it was investigating the matter.
Frances, who works as a writer, told the Echo: "The temperature outside was hovering around zero degrees and ice and snowfall throughout the day had made driving treacherous.
"Numerous crashes had been reported on the M6 and travellers were being warned on the news to be prepared.
"Most shops were shut at that time so I decided to warm myself up with a coffee from one of the numerous branches of drive-thru McDonalds along my route towards the motorway.
"I joined the long queue of cars lining up at the Walton Road branch and ordered a Latte.
"As I approached the payment window I saw that there was a homeless man lying there in a corner under a scant and tatty sleeping bag, looking absolutely frozen and desolate.
"He was very slight, clean shaven and neat, aged only in his mid twenties, but with a vacant look in his eyes as though he was trying to transport his mind elsewhere, far away from the dire situation he was in.
"I asked the cashier at the window if I could add a meal and hot drink for this guy onto my payment.
"She was unequivocal. 'No you can’t and we ask people not to buy them food because they can become aggressive'.
"I was lost for words, except to say 'he’s a human being not a f****** herring gull for God's sake'.”
Frances said she left the McDonald's in disgust and headed to a KFC across the car park, where she ordered a bucket of chicken pieces and a coffee for the man.
She said: "He actually burst into tears when I reappeared with it and I was so sad for him that I wept too.
"If I hadn’t been so upset and affected by this tragic tableau I would have demanded to see the manager and probably caused a bit of a scene.
"But I was so dumbfounded and shocked by the coldness of the staff there that I simply drove away, back to my comfortable warm home, feeling terrible that I couldn’t have done more."
A McDonald's spokesman said: "There is no policy in place that would restrict service to any customer, and we are currently looking into this incident.
"We strive to be a good neighbour and aim to actively support vulnerable people in our communities, in partnership with local organisations and the police."
McDonald's also highlighted that the Walton Road team are "active members of the local community" and have supported both The Salvation Army Walton and Alder Hey House Children’s Hospital with food donations.