The Dutch Old Masters dealer Jan Six says he’s discovered that a painting previously attributed to a “Netherlandish School” is actually by Rembrandt.

Six spotted the work, titled Let the Children Come to Me, at German auction house Lempertz in 2014, where it was being sold with a pre-sale estimate of €15,000-20,000. He and an investor bid the canvas all the way up to €1.5 million, beating out underbidder Otto Nauman, a renowned Old Masters dealer in New York.

Six, who is based in Amsterdam, made similar headlines in May when he announced the discovery of the first previously unknown Rembrandt to emerge in nearly 50 years. Six had bought the unsigned and undated 17th-century canvas, Portrait of a Young Gentleman, at Christie’s in 2016 for just £137,000 ($172,000). Rembrandt scholar Ernst van de Wetering later attributed it to the Dutch master.

The dealer says he recognized the most recent painting as a Rembrandt when he spotted a figure in the background of it who bore a resemblance to the young artist. While looking at an enlarged image from the online auction catalogue, “I thought, ‘Hang on, he’s such a young man, around 20. Who would paint Rembrandt in a picture then?’ Because Rembrandt wasn’t famous at that moment, so the only person who could have done that is himself.” Six added that the master “did this regularly in other paintings.”

Rembrandt experts Ernst van de Wetering and Bob van den Boogert agreed with the dealer, while X-ray and MRI scans also supported the claim. The technical analysis revealed as well that the work had been clumsily overpainted and, almost four-and-a-half years since Six bought it, experts are still working to clean and restore the canvas.

For Six, his second Rembrandt discovery in four years could be a career-defining moment. After all, prior to his re-attribution of Portrait of a Young Man, the last Rembrandt discovery was in 1974. “I can only say that I’ve been obsessed with Rembrandt for a long time and I think that if you do a lot of research, which I have done, you develop a better sense of what you’re looking at,” he said. “I just do my job. I try to find pictures, I try to prove them, and in these two cases it worked.”

The painting will go on view at the Museum de Lakenhal in Leiden, Netherlands, in November 2019.