Even by the demanding standards of the 1960s, Flamingo was considered a groundbreaking magazine. Mixing glamour, sex advice, culture and international politics, it was one of the first magazines to target Britain’s African-Caribbean community.

It ran from September 1961 until May 1965 and at its peak sold up to 20,000 copies in the UK and 15,000 in the US. It was also distributed in the Caribbean and West Africa, and published dedicated editions in Nigeria, Ghana and Liberia. It carried interviews with Malcolm X and advertisements for Island Records, which brought Jamaican ska music to Britain.

But now it has emerged that Flamingo blazed a trail for another extraordinary reason: its founder, Peter Hornsby, was an agent for the intelligence service, MI6, which used the magazine to push an anti-communist agenda among black and West Indian communities.

The revelation came to light after Hornsby’s wife, Jennifer, contacted Stephen Dorril, an author and senior lecturer in the journalism department at Huddersfield University, and told him of her husband’s exploits.

“After the Notting Hill riots [in 1958] it was thought by my husband and MI6 that something had to be done with regard to helping the West Indian community,” she told Dorril, an expert on the intelligence services who later received a copy of her private memoirs from her son, which contained fascinating details of Hornsby’s life as a spy. Peter died in 2000, Jennifer in 2014.

Police search a youth in Talbot Road, Notting Hill during race riots of 1958, which prompted the birth of Flamingo. Photograph: Getty Images

“There were people inside MI6 who saw which way Africa was going in terms of politics and nationalism, and were willing to support black students, writers and aspiring politicians who were on the left but who could be persuaded to oppose communism,” Dorril told the Observer.

“They had links to centre-left politicians and student leaders in this country who were anti-racist and opposed to the white regimes in Africa. Through subtle propaganda activities such as Flamingo, support could be given to such social democrat initiatives while at the same time providing a pool of potential recruitment both here and in Africa and the Caribbean, where the CIA – MI6’s main rival – was a recent interloper.”

Hornsby, whose early MI6 handler was George Blake, the Soviet agent, had been groomed by the intelligence services after being elected national treasurer of the National Union of Students in 1955.

The following year he took up a post with the Coordinating Secretariat of the National Unions of Students (Cosec), an international anti-communist organisation based in the Dutch city of Leiden, which was also funded by MI6.

In the mid-1960s, the Soviets leaked an internal MI6 document – which Dorril believes was “almost certainly purloined by Blake” – acknowledging that it was “of paramount importance to maintain as far as possible the illusion of Cosec’s complete independence”. The document continued: “It seems to us that, if once we attempted to sharpen Cosec as a cold war instrument, we might find it had ceased to have any point at all. Certainly it would be difficult to retain the alliance of member organisations in the uncommitted countries of Asia and Africa, if they suspect that Cosec was being ‘run’ by the Americans and ourselves.”

George Blake, the Soviet agent, who was Flamingo founder, Peter Hornsby’s early MI6 handler. Photograph: Hulton Deutsch

But Cosec was only one avenue that MI6 was keen to explore with Hornsby. In 1960 another one of his handlers, Margaret Bray, who had once been Kim Philby’s secretary, discussed with Hornsby the idea of setting up a magazine aimed at Afro-Caribbean readers. In addition to pushing an anti-communist agenda, it was a means of monitoring national movements and providing access to potential recruits who could be turned into assets.

“In Peter’s mind, a magazine focusing on immigrants would make them feel welcome and ease their integration into British society,” writes Jennifer Hornsby.

A company, Chalton Publishing, was set up to produce the magazine and Edward Scobie, a Dominican who had published Tropic, the first major black journal in Britain, was recruited as editor. Chalton also published Feline, a soft porn magazine aimed at the black community.

David Yellop, Flamingo’s art and production manager, told Dorril that Scobie’s attitude to journalism was very “relaxed” and that “attractive young West Indian party girls” were often to be found hanging around the monthly magazine’s office.

Dorril said Flamingo was part of a wider programme by the intelligence services to reach out to the black community and dissidents. “In London in the early 60s, community centres were funded through CIA-approved foundations. They served as a contact point for musicians, authors and other refugees from places such as South Africa. While there is no evidence that they knew of the intelligence background, it is fairly obvious that such activity would be of great interest to MI6 and the CIA.”

Shortly before he died in 2001, former senior MI6 officer Montague Woodhouse confirmed to Dorril that the service had run a number of joint operations with the CIA, including sponsorship of the literary magazine Encounter, founded by American political essayist Irving Kristol and English poet Stephen Spender.

Encounter’s links to both US and British intelligence were exposed in 1967 and led to Spender’s resignation. By that stage Flamingo had closed, ostensibly because it had become financially unviable but possibly because suspicions about its covert funding were starting to emerge.

When Flamingo closed, Hornsby’s work as an agent with MI6 also seems to have ceased. He started an antiques business with his wife and became an acknowledged expert on English pewter.

There were changes in the magazine in 1964 when its political articles dealing with Africa and the Caribbean became more serious and often had no byline. They are similar in content and style to the material given to media outlets by the Foreign Office’s semi-secret propaganda unit, the Information Research Department.