ON November 24, 1983, the then Vanity Fair editor Tina Brown attended a lunch in London, thrown by Henry Kissinger and his wife Nancy. “I feel Henry is in a lot of pain from Seymour Hersh’s devastating book, The Price of Power," she confided to her diary. "He looks tormented.”

Less than two months later, Brown was at a dinner in New York, and the conversation turned to Kissinger – specifically, this time, to his reported reaction to Hersh publishing a confidential report of Kissinger’s in the New York Times. “Henry,” she wrote, “drove straight back to the city [from Connecticut] in a murderous rage.”

Kissinger’s grief and outrage typify the reactions that many in the US political, military and intelligence establishments have experienced over the decades at the hands of Hersh, an investigative journalist par excellence. By doggedly pursuing leads, sources, witnesses and documents, by calling on his unrivalled wealth of contacts, and by getting people to talk to him, he has been responsible for an astonishing list of exposes in magazines and newspapers, from the My Lai massacre by US soldiers in South Vietnam in 1968 to the grotesque abuses meted out to detainees at Abu Ghraib prison in Iraq in 2003.

As the New York Times, his old newspaper, wrote of his newly-published memoirs last week: “His chosen areas of investigation were often the hardest to penetrate: He burrows away at the secrecy of the state, the military, intelligence, foreign policy and giant corporations. Over nearly six decades he exposed brutality, deception, torture, illegal surveillance, government-sponsored fake news and much else.” In the book, Reporter: A Memoir, Hersh himself says his career "has been all about the importance of telling important and unwanted truths and making America a more knowledgeable place".

He details the lengths he went to in order to write about My Lai. A tip-off alerted him to the fact that First Lieutenant William L.Calley had been charged by the US army over the deaths of an "unspecified number of civilians" in Vietnam. In the office of Calley's lawyer, the charge sheet lay on the man's desk, facing away from Hersh. For 20 minutes the journalist chatted with the lawyer, pretending to take notes, while furtively copying, word for word, the upside-down charge sheet.

Calley himself seemed to have vanished but Hersh eventually found him, and the full story began to emerge.

What had happened was that an infantry company had killed up to 500 unarmed women, children and old men while on a search-and-destroy mission. Some 20 women and young girls were raped. Hersh's five authoritative reports on My Lai stunned America and won him the 1970 Pulitzer Prize for International Reporting – "a rarity for a freelance journalist", he writes in his book.

Hersh was born in Chicago. His Lithuanian father and Polish mother had both arrived at Ellis Island after the Great War. He started out as a copy-boy in the city and worked for news agencies before turning his attention to America's "hidden arsenal" of chemical and biological warfare, the subject of his first book. My Lai was his second.

As a reporter he turned his attentions to everything from Watergate to illegal surveillance programmes. He wrote about the secret bombing of Cambodia and the CIA's clandestine war against the Allende government in Chile. In six days in May 1973 he had five page-one news-making stories on Watergate in six days in the New York Times. Further awards followed.

He wrote books about Kissinger in the White House (The Price of Power) and about Israel's nuclear option. His 1997 book, The Dark Side of Camelot, cast John F Kennedy in a new light. Novelist Gore Vidal said Hersh "has found more muck in this particular Augean stable than most people want to acknowledge." Hersh spent five years on the book, and carried out more than 1,000 interviews.

The 9/11 terror attacks and the 2003 invasion of Iraq prompted many Hersh articles on national security for the New Yorker. He interviewed many prominent Middle East leaders, including the Syrian President Bashar Assad. His 2004 report on the brutalities and the sexual humiliations inflicted on Iraqi prisoners at Abu Ghraib made headlines around the world.

His most recent book, 2016's The Killing of Osama bin Laden, challenged the official version, handed down by President Obama and the Pentagon, about the killing by US Navy SEALs of bin Laden in Abbottabad, Pakistan, in May 2011. The book was dismissed as "utter nonsense" by the CIA and as having “too many inaccuracies and baseless assertions” by the Obama White House.

In his memoir Hersh recognises that he is a survivor from journalism's "golden age", when reporters had the luxury of time and he could travel anywhere in pursuit of a story. He laments the practice of newspapers and TV networks of slashing the numbers of newsroom staff, and hates the tide of "fake news, hyped-up and incomplete information, and false assertions delivered nonstop" by the media - and President Trump.

And he adds: "Where are the tough stories today about America's continuing Special Forces operations and the never-ending political divide in the Middle East, Central America and Africa?" If anyone can find them, Hersh surely can.