The 'Burley Banksy' said he has been left "disheartened" - after one of his Leeds United murals was covered in red paint.
Despite being a self-confessed amateur, huge Leeds United fan Andy McVeigh, 49, has spent the last 12 months coming up with creative designs to paint over graffiti or brighten up the dull electrical boxes and bollards.
Dubbed the 'Burley Banksy' by his friends due to his art-style and elusiveness, Andy creates pieces for iconic moments throughout the history of the club.
However, Andy was shocked to discover one of his pieces had been ruined with red paint over the weekend.
The 'We All Love Leeds' electrical box has been fully covered in red.
Andy said: "I just don't know who would do it.
"The fact any artistic piece is ruined is always disheartening.
"I have received a lot of support from Leeds United fans."
Andy said he has also been the subject of 'trolls' on Twitter, with many fans joking about the shocking cover up.
He added: "There have been a lot of people on Twitter trying to wind me up about it.
"I was pretty gutted obviously because the piece took me ages to do.
"I have been surprised by tweets from Manchester United fans mocking me.
"Maybe I am naive but I wasn't expecting unprovoked unpleasantness.
"I can't believe it.
"I've never been trolled before because I'm doing something positive for my city.
"It's quite an experience!"
Andy has vowed to return to the site to repaint the box as soon as possible.
He said: "Even my son couldn't understand why anyone would do it.
"It is just someone being an idiot but it is disheartening.
"If he wants to get in touch I'll buy him a coffee and we can have a chat about why he felt the need to do it.
"There's obviously some insecurity and other issues there."