American forgery heavyweight, Tony Tetro, claims to be behind the paintings and actually came forward to reveal that the artwork is fake.
"You can impress your friends with my pictures, decorate your homes with them, but they would never pass expert scrutiny," Tetro, who was once sentenced to six months in prison for art forgery, told the tabloid.
So how did the paintings end up at the 18th century royal residence?
According to the artist, British businessman James Stunt, who declared bankruptcy earlier this year, purchased all three several years ago and later went on to loan them to Dumfries House.
"There is no question about it: James knew [the paintings] were mine," Tetro continued, accusing Stunt of conning Prince Charles.
Amid speculation, the paintings in question - alongside 14 others loaned from Stunt on a decade-long lease - have since been taken down from public view.
A spokesperson for the Prince's Foundation has since released an official statement in response to the scandal.
"Dumfries House accepts artwork on loan from time to time from individuals and organizations such as the Scottish National Gallery," the statement reads.
"It is extremely regrettable that the authenticity of these particular few paintings, which are no longer on display, now appears to be in doubt."