US billionaire David Koch, a major conservative donor, has died, according to media reports.
The controversial industrialist who alongside his brother Charles used his influence and money to help Republican causes, passed away age 79.
Charles, 83, confirmed his brother’s death in a statement on the Koch Industries website.
“While this is a very sad day for us all, I want you to know that David was proud of the extraordinary work you all have done to make Koch Industries the successful company that it is today,” he wrote.
The brothers often became the focal point of liberal ire in the US, over their lobbying for lower taxes, less regulation and free trade.
However in recent years the brothers, often seen as kingmakers in the past, have clashed with US President Donald Trump over his protectionist policies.
Trump has in the past slammed the brothers as “globalists” who are against strong borders and powerful trade.
“Their network is highly overrated, I have beaten them at every turn,” he said in 2018. However the Kochs found common ground with Trump over his plans to pull out of the Paris climate change agreement.
Charles took over most of the running of Koch industries in June last year as David stepped aside from the company and the brothers’ political group over poor health.
His death comes nearly three decades since he was diagnosed with prostate cancer.
Koch Industries was founded by the brothers’ father Fred Koch in 1940. The oil refining company was later taken over by Fred’s four sons. However Charles and David bought their brothers out.