English novelist, journalist and former spy Frederick Forsyth, who is known for his well researched thrillers, died at the age of 86 on June 9, media reports said.

"We mourn the passing of one of the world's greatest thriller writers," Forsyth's agent Jonathan Lloyd said as quoted by several media.

He died after a brief illness, a statement said.

Forsyth's career, which spanned journalism, military service, and even covert intelligence work, was marked by an amalgamation of fiction and authenticity in his thrillers.

Hugely known for his debut novel The Day of the Jackal (1971), Forsyth published 14 novels and sold more than 75 million copies worldwide.

Forsyth had shared that he wrote his debut novel when he was out of job.

"(I was) skint, in debt, no flat, no car, no nothing and I just thought, 'How do I get myself out of this hole?' And I came up with probably the zaniest solution - write a novel," he had said as quoted by BBC News.

The Day of the Jackal was made into a film starring Edward Fox as the Jackal in 1973 and also a TV drama featuring Eddie Redmayne last year.

Being a fighter pilot, a war correspondent and a spy, Forsyth utilised his immense experience in shaping his novels that also dealt with espionage, military strategy and politics.

A precise storyteller, Forsyth's notable works include The Odessa File, The Dogs of War, The Fourth Protocol and The Fist of God.

Born on August 25, 1938, in Ashford, Kent, England, Forsyth attended Tonbridge School, a prestigious boarding school in Kent.

His early fascination with aviation prompted him to join the Royal Air Force, where he served as a pilot officer from 1956 to 1958, flying the de Havilland Vampire.

Following his military service, Forsyth moved to journalism, first working for Reuters in 1961 and later for BBC as an assistant diplomatic correspondent.

His assignments included reporting on the attempted assisination of former French President Charles de Gaulle and the Biafran War.

Forsyth shared in his interviews that he had worked for the British Intelligence Agency MI6 and also covered the Nigerian civil war in the 1960s.