A man serving jail time for armed robbery has won this year’s coveted Doug Moran National Prize for portraiture.

The prize was established by Doug and Greta Moran in 1988 to foster portraiture skills and excellence in photography.

The $150,000 prize has been won by Nigel Milsom for his portrait called Uncle Paddy.

The portrait depicts his grandfather’s friend, who he says would drink with him every Saturday night.

A spokeswoman for the award says he painted the portrait before going to jail.

Judge Daniel Thomas says he was struck by the gentleness the artist captured.

He says he was also impressed by the incredibly skilful brushwork.

“The black and white painting looked like a kind of cubism, like a stiffened-up line work of a head,” Mr Thomas said.

“But the white ended up a bit like softened cubism turned into flames, flaming cubism.”

The winning portrait is now the property of the Moran Arts Foundation and will be exhibited permanently as part of its collection.

Photographer John Janson-Moore was awarded $50,000 for the Moran Contemporary Photographic Prize.