Civil rights activist Darcus Howe has died aged 74, according to his biographer.
Robin Bunce said Mr Howe died in his sleep on Saturday, adding that the news had been confirmed by Mr Howe's wife Leila Hassan.
Mr Howe was born on 26 February 1943 in Trinidad and came to the UK in 1961, beginning a career in journalism seven years later.
His first job was at the Notting Hill-based magazine The Hustler.
He was editor at Race Today for more than a decade, and more recently was a columnist for The Voice newspaper.
Mr Howe also had regular columns at the New Statesman and the Evening Standard.
Dr Bunce, who co-wrote the biography - Renegade: The Life and Times of Darcus Howe - with Paul Field, said Mr Howe had been a "grass roots" activist in the 1970s and 80s.
He added: "I think he's also important in the 80s, 90s and 00s, because he brought a radical voice, a voice for egalitarianism and justice to the mainstream media."
Mr Howe wrote about his 2007 prostate cancer diagnosis and the treatment that followed in an article for The Guardian in 2009, which he also used to encourage black men to get tested for the disease.
Dr Bunce, a historian at Homerton College at the University of Cambridge, told the Press Association: "On a personal level, Darcus was enormously warm and generous and he loved life.
"It was a real privilege to get to know him."
The shadow chancellor, John McDonnell, wrote on Twitter that Mr Howe had been "a courageous campaigner against injustice and for equality and civil liberties over decades".
Shadow home secretary Diane Abbott described him as "one of the standout activists and public intellectuals of his generation".
George Galloway tweeted that Mr Howe was a "fighter against racism and imperialism", a "civil rights champion" and a "great leader of black peoples around the world".
Mr Howe was remembered as "an important voice as many of us were growing up" by actor Adil Ray and a "great broadcaster and visionary" by presenter June Sarpong.