An ex-councillor from Brighouse struck lucky with a sketch he bought from an art fair.
Former Calderdale deputy mayor Nick Yates, 70, was looking through some framed pictures at a Harrogate fair when he came across an eye-catching pencil drawing.
A keen Hockney fan who recognised the quirky style, Nick snapped it up and later took advice from his local gallery.
And it seems Nick’s eye for the unusual has paid off, after the Harrison Lord Gallery in Brighouse said the sketch could be an original mock-up for one of Hockney’s most famous paintings, A Bigger Splash.
Nick bought the picture for £2,750 – but if it’s a genuine Hockney it could be worth £75,000.
The sketch will now go on show at the Bradford Road gallery to mark the opening of the Brighouse festival this Saturday.
Nick said: “I have been a huge Hockney fan since the 60s and own a copy of A Bigger Splash, so I recognised the similarities straight away.
“It wasn’t cheap, but I wouldn’t have bought it if I thought it was a fake.”
Gallery owner Steven Lord said he was convinced the sketch was genuine.
He said: “The composition is almost identical. In the pencil sketch there is more image to the right than in the finished painting but there is clearly a fold in the paper at the point where Hockney decided to crop the image.
“It is signed with Hockney’s rather unusual signature with a greeting so we can assume that he gave it away as a little momento.”
The drawing also has smaller sketches on the back, which Steven said is “typical” of artists playing with ideas before putting them onto canvas.
Further proof of authenticity is in the frame which came from a Manchester gallery owned by Hockney’s friend, the late Jonathan Silver.
Mr Silver was an art enthusiast who purchased Salts Mill at Saltaire, where Hockney’s work is now housed.
After the picture has been exhibited, Nick plans to send the picture off to London for a final opinion and valuation.
He added: “I’m not sure what I’ll do with it if it’s confirmed to be genuine.
“I feel lucky it has landed in my hands, but I’m not sure I could afford to insure it.”
A Bigger Splash is described as a large “pop art painting”, which was painted in California in 1967 as part of a trio.
Set on a sunny day with a cloudless blue sky, the painting depicts a pool in front of a house with a big splash where a person has dived from a yellow diving platform.