Timothy Mellon, a reclusive billionaire and a major financial backer of Trump, has been identified as the mystery man who donated $130 million to help fund the US military amid the ongoing government shutdown, the New York Times reported.

The billionaire had made the donation anonymously. Trump announced the donation on Thursday and referred to him as a “patriot”, a “great American citizen,” a substantial man, and a friend.

Trump said that he didn't want publicity.  “He prefers that his name not be mentioned, which is pretty unusual in the world I come from, and in the world of politics, you want your name mentioned,” he said.

The donation was made to ensure that the active duty service members would continue to receive their pay during the budget deadlock, which had suspended government operations.

Pentagon's chief spokesperson said that the “donation was made on the condition that it be used to offset the cost of service members’ salaries and benefits,” the funds amount to $100 per service member.

Many government workers have been furloughed or told to work without pay during the shutdown.

The donations have been controversial. Delaware Senator Chris Coons, the top Democrat on the Senate's defence appropriations subcommittee, said, "Using anonymous donations to fund our military raises troubling questions of whether our own troops are at risk of literally being bought and paid for by foreign powers."

Donations over $10,000 also have to be reviewed by ethics officials according to rules of the Defence Department “to determine whether the donor is involved in any claims, procurement actions, litigation, or other particular matters involving the Department that must be considered before gift acceptance."

Timothy Mellon, 81, a billionaire heir, is the grandson of the former US Treasury Secretary Andrew W Mellon and a descendant of Thomas Mellon, an Irish immigrant who built a vast banking and real estate empire after arriving in the US in 1818.

The Mellon family is the 34th richest family in the US, according to Forbes and is worth over $14 billion.

Mellon studied city planning at the Yale university. His father was a benefactor to the institution and funded the Yale Centre for British Art. In 1981, he founded Guilford Transportation Industries, which went on to acquire major railroads across Canada, New England, and the mid-Atlantic. Later, it acquired the Pan American World Airways. Mellon had also served as a trustee for the Andrew W Mellon Foundation for 21 years before stepping down in 2002.

The billionaire recluse left his native Connecticut to live in Wyoming in 2005 and has been living there ever since.

Mellon was the largest donor in the 2024 electoral cycle after donating about $165 million to Trump, Robert F Kennedy, and other Republican candidates, The Guardian reported. $125 million out of this was given to Super Pac Make America Great Again Inc, which supported Trump, according to federal documents.

Mellon also has an extensive history of donating to conservative causes and candidates.

He donated about $1.5m in 2010 to the state of Arizona to defray the legal costs to defend a controversial anti-immigration bill, the BBC reported.

In his 2012 memoir, he highlighted his political views. He condemned what he called Slavery Redux social safety net programmes. He also said that Black voters were given freebies in exchange for votes.

Occasionally, however, he has also donated to Democrats. He gave about $2,700 to progressive New York Representative Alexandria Ocasio-Cortez's 2018 campaign. She had tried to return the donation, he told Bloomberg in 2020. He refused to cash the cheque.