Prince William has been snapped selling the Big Issue in central London this morning, sporting a red seller's vest and hat and a bundle of magazines.
Twitter user Danny O'Connor spotted the Duke of Cambridge accompanying a Big Issue seller, tweeting: "Just Prince William on the streets of London doing some work for Big Issue.
"Quite mad given the normal amount of security he has – apparently spent the day out."
The Duke maintained a low profile while conducting duties in central London, only being spotted by the brother-in-law of Retired Met Police Chief Superintendent Matthew Gardner, who shared photos via his LinkedIn account.
Writing on LinkedIn, Mr Gardner said: "What an honour to have a private moment with our future King who was humble and working quietly in the background, helping the most needy.
"These ‘silent gestures’ often go unrecognised."
He added: "The finale to this unique occasion was when Prince William asked my brother-in-law if he wanted to buy the ‘Big Issue’, to which he replied: 'I have no change.'
:At this point William produced a mobile card machine… you cannot teach that!"
Commenting on William's interaction, he concluded: "Priceless, or should I say ‘Princely’."
The Duke of Cambridge has been an advocate of projects supporting the homeless, since his mum Princess Diana introduced him to rough sleepers in the capital as a child.
In 2019, the Prince became a royal patron of initiative the Passage, in Victoria, adding to his role as patron of Centrepoint homeless charity.
Comments on Mr Gardner's post praised William for assisting Big Issue sellers without "fuss, fanfare or publicity".
Nicholas H added: "Love this! Another great example of leadership and very inspiring."
Prince William was spotted sporting the Big Issue outfit, wielding a handful of magazines
Danny O'Connor/Twitter
Prince William selling copies of the Big Issue
Vitalijus Zuikauskas/Instagram