Tributes are pouring in for Peter McLeavey – the gentleman art dealer who discovered some of the biggest names in New Zealand art.

McLeavey, 79, died overnight on Thursday after a long battle with Parkinson's Disease, but right until the end he kept a keen interest in art and his Wellington gallery.

As well as being known for his backing of a young Colin McCahon, McLeavey's landmark gallery, up a narrow staircase on Cuba St, has long been considered Wellington's, if not New Zealand's, most influential dealer gallery.

Tom Hunt The Cuba St gallery, which Peter McLeavey made his life's work, had a black banner hung from it to mark his death.

A statement released by the family on Friday said he accepted the decline in his health without complaint.

"The gallery was his theatre. He wove compelling stories around the art... He said he had had a wonderful life doing what he loved."

Obituarist Peter Kitchin had known the art dealer since he moved to Wellington in 1981, and said McLeavey was a great art dealer who never took any nonsense from anybody.

FAIRFAX NZ Wellington art dealer Peter McLeavey has died.

"That's quite a feat given the industry he worked in," Kitchin said.

"One woman had a show and wanted to put up her art herself and she painted his couch, so he cancelled her show.

"He was very particular about his standards, but could be playful and amusing like people are."

Supplied A young Peter McLeavey with paintings by Toss Woollaston.

McLeavey would speak in sound bites and often had answers ready for questions, just on the off-chance a journalist would ring, Kitchin said.

"Instead of making a rash statement about something he had a very considered and rather learned way of explaining something. He could do high-end art for idiots in three sentences. It was astonishing, because no-one else does it."

On Twitter actor Sam Neill paid homage to his friend.

ROSS GIBLIN/FAIRFAX NZ Peter McLeavey receives the ONZM from the Governor General Sir Jerry Mateparae in 2012.

"A great man gone. Peter McLeavey did more than anyone to make NZ art contemporary. The country owes my friend a great deal . I'm sad today.[sic]"

Many other galleries and members of the art world also took to Twitter to express their sadness at McLeavy's death, including The Dowse Museum, Wellington's City Gallery and Auckland Art Gallery.

As McLeavey battled Parkinson's his daughter Olivia took over running the gallery – which she will continue to do.

McLeavey began dealing in art in 1966 from a flat on The Terrace and opened the Cuba St gallery in 1968 with a show of Toss Woollaston's work.

Other early artists were Colin McCahon, Milan Mrkusich and Gordon Walters. He also showed Michael Smither, Richard Killeen, Len Lye, Ian Scott, Robin White, and Bill Hammond.

His biographer Jill Trevelyan – whose work on McLeavey won the New Zealand Post Book Awards book of the year award in 2014 – went to visit him in hospital a week ago.

Right up to the end he had kept a keen interest in arts, culture, and even contemporary music.

Even as he got increasingly sick, McLeavey would make his way up the gallery stairs to help hang exhibitions.

Trevelyan remembers walking up those same stairs in the 1980s when the gallery was the "number one place to go".

She remembers McLeavey as being "in the corner, a little inscrutable person who was always interested in what people were doing".

"He had an amazing curiosity."

While New Zealand's big names in art have all exhibited at the gallery, McLeavey was always keen to discover young upcoming artists.

"He was always interested in bringing on new people – he was always out visiting new people."

In 2009, a documentary by Jan Bieringa was released about McLeavey.