A LEADING portrait painter vowed yesterday never to paint another commission for the National Portrait Gallery after suffering “unforgivable” treatment by its director.

Michael Reynolds, whose sitters have included Lord Denning and Paul Eddington, accused Sandy Nairne, the gallery’s director, of interfering after commissioning him to paint the conductor Bernard Haitink.

Recalling his shock at being told, on delivering the painting, that the “format needed changing”, Reynolds said: “Unaccustomed to Art Newspeak, I asked if it meant what I thought it meant. ‘Yes’, he [Nairne] replied, ‘it needs cutting down. There’s too much desk in front of Haitink and the head needs sharper delineation’.” Astonished, Reynolds replied: “It is the shape of the work that holds the design, which is itself the portrait. Nor does any head need a full outline.”

On being told by the director that gallery trustees who knew Haitink were unhappy with the work, and armed with a list of their names, he had contacted the conductor to ask how well he knew any of them. “He had not heard of one of them,” he said.

Haitink, whose posts have included music director of the Royal Opera House and Glyndebourne, as well as conducting some of the world’s leading orchestras, such as the London Philharmonic and London Symphony Orchestras, told Mr Nairne that he was pleased with the portrait.

Reynolds made several visits to the conductor’s home, producing a portrait entirely from life. The artist said that he then had to wait almost a year to be paid. He had suffered the stress of having repeatedly to ask the gallery for his promised payment. Eventually he had stormed into the gallery and demanded to see the director. “A security guard was rushed in to me but what could he do?” he said. “I had no weapon. I was not violent and I was courteous, though my voice was penetrating clearly into the adjoining galleries.”

He had then discovered from the gallery that it had paid the money into an account unknown to him. He also believes that the gallery damaged the painting in wrenching it from its packing. The gallery says that the damage happened in transit.

After an initial exhibition, where the painting was described by one critic as “an intensely moving performance because of its architectural integrity and musical momentum”, it is no longer on display.

Reynolds tells the full story in The Jackdaw, and David Lee, the editor of the magazine, said: “If it had been by Lucian Freud, would they say to him, ‘Take a bit off the bottom and finish off the vague head’?”

Mr Nairne said: “We are very sorry to hear he’s still worried . . . He produced a very fine portrait.” He said that the portrait gallery commissioned about eight portraits a year, finding the appropriate artists for distinguished sitters. “It is absolutely common that we would discuss with an artist where we had a view,” he added. The artist, he recalled, had talked “interestingly” about why he felt the composition should remain unchanged. “Michael expressed strongly why it should be the way it was and I accepted that,” he said.

As the collection is rotated repeatedly, the portrait would go on display again. The public “like it very much”, he said.

He dismissed the delayed payment as a confusion over bank account details.