Portrait of barrister Charles Waterstreet wins 2015 Archibald Prize

Newcastle artist Nigel Milsom has won his first Archibald Prize for his portrait of Sydney barrister Charles Waterstreet.

Mr Milsom's victory in the prestigious art competition was announced today by the Art Gallery of NSW.

He will receive $100,000 for the prize.

The portrait of Mr Waterstreet was the largest canvas among this year's 47 finalists.

The pair formed a close bond after Mr Waterstreet represented the artist, during his trial for armed robbery.

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Milsom served six years in jail after being found guilty of holding up a Glebe convenience store under the influence of drugs.

Mr Milsom said his portrait was an attempt to depict the "very complex" Watersteet as "part-man, part-mythical creature, with hands that appear otherworldly".

The painting was titled “Judo house pt 6 (the white bird)”.

"He is a very complex person, he isn't just a law man," Mr Milsom said.

"He's a writer, a social environmentalist and does things in film, photography and theatre too. Despite his busy life, he has managed to dedicate most of his time to the welfare of others."

The gallery's Board of Trustees president Guido Belgiorno-Nettis congratulated Mr Milsom on his achievement.

"It’s a magnificent painting," he said.

"It’s powerful; it’s commanding and we’re proud to have it in this year’s exhibition.”