A reclusive mathematician, investor and high-end gambler, the 47-year-old has emerged as the territory's largest individual political donor of the past five years.

Despite living a long way from Canberra - in an award-winning luxury home on the Gold Coast hinterland - his name can be found in the latest release of ACT Electoral Commission donation disclosure reports.

He gave $30,000 to the ACT Greens last year, as first time candidate and former GetUp! leader Simon Sheikh ran for an ACT Senate seat.

An ACT Greens spokeswoman said no one from the party had met Mr Turpie, but they were aware of some of his wealth came from gambling.

The donations are only the latest in his record of support for progressive causes, including his 2007 purchase of left-wing online magazine New Matilda and a $25,000 donation to GetUp! to help launch the advocacy group headed by Mr Sheikh in 2007.

While little is known about Mr Turpie, his professional contacts fall across the Australian political divide.

Mr Turpie did not respond to multiple requests for an interview from The Canberra Times.

More than a dozen acquaintances and friends in Australia and overseas said Mr Turpie, born in Canberra in November 1966, is acutely private.

Described as a maths whiz who has been left-leaning since university and "lucked out deluxe" creating specialist algorithms, Mr Turpie is reportedly part of the secretive Punters Club which came to the attention of the Australian Tax Office in a 2012 court case over reported activity of $2.4 billion a year.

The ATO accused the club's 19 members of owing hundreds of millions in unpaid taxes after using software to maximise winnings. It alleged club members withheld information to give the impression its activities were recreational gambling.

The case settled in October 2012.

Mr Turpie is no stranger to betting. In 1995 he co-authored an academic paper on the quality of blackjack in Australian casinos.

A detailed study of the 6129 hands of blackjack in four casinos, the paper considered how a player's sex, race, bet size and personal characteristics impacted on the ability to win.

The highest-profile Punters Club member, art collector and founder of Tasmania's Museum of Old and New Art David Walsh, said his friend hadn't lived in Canberra for years.

"You are probably a million to one in trying to get him to talk to you," Mr Walsh said.

"I have known him for maybe 15 years and he's a very likeable guy. He's very quietly spoken and very private, which is why I am surprised that he made a donation which is publicly recorded."

He said Mr Turpie was shy and "a classic nerd".

"Duncan is probably the least controversial human being I have ever met. He likes to spend all his time with his wife on a little farm ... and as with many people with mathematical skills, he's obsessive compulsive so that might be one of the reasons he doesn't like talking to people."

Mr Turpie gave a further $5000 to the federal Greens for the 2013 election and Australian Securities and Investments Commission records show he is the sole director of Complex Number Pty Ltd.

Most of his $30,000 donation went to the ACT Greens federal accounts, which under the territory's election laws mean it can only be spent on administration or federal elections.

Greens convenor Sophie Trevitt said Mr Turpie did not meet Mr Sheikh.

She said the party's donations review body approved taking the money despite his gambling profits.

"Mr Turpie is a private individual, has donated money to a range of philanthropic causes and the sole purpose of the donation was to support the aims of the Greens party. The donation was accepted no strings attached," Ms Trevitt said.

Future donations from Mr Turpie would be considered on a case-by-case basis she said.

The Australian investigative journalist Hedley Thomas was a classmate of Mr Turpie in Canberra in the late 1970s and remain in occasional contact.

"He has always struck me as a dedicated and compassionate supporter of progressive causes.

"[Mr Turpie] does his best work out of the limelight, and prefers to keep it that way," Mr Thomas said.