David Koch, one half of the double act of the billionaire Koch brothers who used their vast wealth as energy tycoons to transform rightwing politics in America with a relentless drive towards free market and libertarian ideals, has died aged 79.

News of his death was first announced by Jane Mayer, the New Yorker writer whose 2016 book Dark Money delved into the shadowy dealings of the brothers, who have become liberal bete noires.

Koch’s death was confirmed in a statement that said he had died from prostate cancer, which he had been diagnosed with 27 years ago yet had remarkably kept at bay until now.

Koch built up the Kansas-based Koch Industries into a massive industrial empire alongside his brother Charles that they inherited from their father Fred Koch and that spanned oil manufacturing, paper mills and other products. The duo were among the richest people in the world, each estimated to have a net worth of more than $50bn.

David Koch used that fortune to support his passion in the arts, with his name emblazoned over the home of the New York City Ballet at the Lincoln Center, as well as philanthropic awards to centers of medical excellence that may have been inspired by his own health battle.

But he and his brother became far better known – notorious even in liberal circles – for the controversial way in which they used their money to become the face of the rightwing super-donor class in the modern era.

Together, the brothers developed a network of conservative campaigns, dubbed by detractors the “Kochtopus”, that worked both at a deeply local and at a national level. Their twice-yearly gatherings of top conservative figures helped to shove the Republican party in a rightward direction, attended as they were by senior figures in the party, major donors and even US supreme court justices.

He was seminal in pushing many of the policies that have become pillars of today’s American conservatism, including giving a leg up to the early Tea Party in 2010, opposing Barack Obama’s widened healthcare provision, Obamacare, and waging a sustained attack on government regulation including attempts to combat the climate crisis.

Koch had stepped away from his political and business affairs in June last year, citing deteriorating health.

In addition to Charles, with whom he forged most of his most memorable activities, David also leaves behind his wife Julia, three children and two other brothers – Frederick and his twin Bill. Those brothers largely kept out of politics and avoided the opprobrium and supplication that David and Charles attracted in equal measure.

The statement from Julia Koch, confirming his death said: “While we mourn the loss of our hero, we remember his iconic laughter, insatiable curiosity, and gentle heart.”

But her reverential words were quickly followed by the start of what promises to be a stream of critical comment.

Alexander Kaufman, an environmental commentator at HuffPost, tweeted: “He deployed his stupendous fortune funding climate denial in the years when the science was clear and there was still time to avert catastrophic warming. He died as fires raged from the Amazon to the Arctic.”