Another well known UK conman/forgery 'mastermind', was John Drewe, who met and manipulated a struggling artist, John Myatt:

https://en.wikipedia.org/wiki/John_Drewe

https://www.youtube.com/watch?v=De3S2kkGQow

https://www.nytimes.com/1999/07/18/magazine/a-20th-century-m...

>'His unorthodox formula of emulsion and K-Y Jelly was fast-drying, allowing him to paint quickly, if obsessively. "I took no trouble technically," he says. "There was a negligence to everything I did."

Even so, his pictures were passing as genuine and selling for tens and hundreds of thousands of dollars. He was enjoying a financial success he could never have approached by painting Myatts. Perhaps no other forger of his or any other time has worked so prodigiously and in so many styles...'