To discover one new painting by Van Gogh is exciting enough. To discover two in one is extraordinary. The finds were announced today.

One work is a still life, a flower painting with a most vibrant palette. The other is a depiction of two half-nude male wrestlers - a painting which was thought to have been lost or destroyed until now.

The wrestlers’ existence was known only from a reference in one of the Dutch master’s letters, written aged 33, just four years before his tragic death. On 22 January 1886, he wrote: “This week I painted a large thing with two nude torsos – two wrestlers.”

There is no other painting of wrestlers. It is this painting that now confirms the still life’s authenticity. They are both on the same canvas. Van Gogh painted the still life over his wrestlers which could not be seen until now.

The still life was acquired in 1974 by the Kröller-Müller Museum in Otterlo, Holland, which boasts one of the world’s largest Van Gogh collections. But the painting’s link to Van Gogh had been repeatedly dismissed over the years because it was thought to be “uncharacteristically exuberant”.

In 2003, it was finally “deattributed” on stylistic grounds and unceremoniously relegated to a back room out of public view, listed merely as “artist: anonymous”.

Now a collaboration between scientists, curators and conservators dispels doubts about the hand of Van Gogh on the surface painting, which is titled Still life with meadow flowers and roses.

The wrestlers have been revealed for the first time due to the latest advances in high-intensity x-ray technology. Detecting pigments in hidden layers of paint, it enables a painting that has been hidden beneath another surface painting to be viewed in unprecedented detail.

From today, for the first time in its history, the flower piece will be given a prominent display among other Van Goghs in the museum.

By the time he wrote the letter, he was in Antwerp, having arrived there in November 1885. In January, he enrolled at the art academy where his teacher encouraged him to purchase a large canvas, new brushes and paint – well beyond the means of the impoverished Van Gogh. The purchase was made possible by his beloved and ever-supportive brother Theo.

Artists like Van Gogh reused canvases, to save money or to conceal a work with which they were dissatisfied.

Doubts about the still life were due partly to the canvas’s unusual size, at 100 x 80 cm. Van Gogh’s Parisian flower still lifes are generally smaller. Historians have now realised that the size of the canvas was a standard format for figure paintings at the Antwerp academy.

Van Gogh painted over his figures several months later, when he joined his brother in Paris, without first scraping off the earlier depiction. The wrestlers were probably painted from life.

The discoveries have been made possible by researchers from the Delft University of Technology, the University of Antwerp, Deutsches Elektronen-Synchrotron (DESY) Hamburg, the Van Gogh Museum and the Kröller-Müller Museum.

Their tests found further clinching evidence. They revealed that the pigments used in both paintings are a perfect match for Van Gogh’s palette. They also show that the brushstrokes on the wrestlers are typical of his hand.

Professor Janssens of Antwerp University said: “For the first time, we could obtain images that reveal how Van Gogh started sketching parts of the wrestlers with broad paint strokes, much in the same manner in which he painted the figures in the oil sketch of the Potato Eaters, which would later become regarded as one of this most important early works.”

Professor Joris Dik of Delft University spoke of the excitement: “What makes it very tangible is this letter which refers to a painting that was thought to have been lost or had not survived.” He said that it was in Paris that Van Gogh became “obsessed” with flower painting, leaving behind his Dutch period, “where he used mostly dark colours”.