The English Football Association tried to impose an unofficial quota system on the number of black players an England manager should be allowed to use, according to a new book about racism within the sport.

Pitch Black, written by Emy Onuora, includes a passage in which one of the sport’s leading anti-racism campaigners claims Graham Taylor admitted to him he had been summoned by two members of the English FA’s hierarchy and told “in no uncertain terms” he should not go beyond a certain limit.

There is absolutely no suggestion that Taylor, with a long history of working with some of England’s leading black players over the past 30 years, adhered to this policy but the book recounts him saying there were senior figures trying to put pressure on him to keep the team predominantly white.

Taylor is said to have revealed this during a function at Watford’s ground during the 1999-2000 season when Richie Moran was the guest speaker. Moran, a Birmingham City player in the 1990s who eventually quite the game because of the racial abuse he suffered, recalls in the book: “Graham Taylor came up to me and said: ‘Look, I’m going to tell you something … I’m never going to admit it, I will be sued for libel.’ He said: ‘When I was manager of England I was called in by two members of the FA, who I won’t name …’ I volunteered two names. He said: ‘I’m not prepared to say, but I was told in no uncertain terms not to pick too many black players for the national side.’”

This also ties in with a Kick It Out function on its 10th anniversary in 2004, attended by Taylor, when it was reported that a former England manager had revealed the same conversation to other guests but declined to go public.

Taylor has been made aware of the book and told the Guardian he could not specifically remember the conversation with Moran. “That is not me trying to evade it – and it also doesn’t mean I didn’t say it – but if anyone looks at my record with club and country it would be obvious to everyone anyway that I didn’t follow what was apparently said. If anyone looks at my record, I could never be accused of blocking the way for any black player.”

Onuora’s book, officially launched on Friday, makes the same point but the allegations do potentially raise serious questions about the attitudes of some English FA figures during a period of the game – Taylor managed England from 1990 to 1993 – when the sport was supposed to be leaving behind the more obvious elements of racism from previous decades. The English FA has been notified about the revelation but has yet to comment.

Onuora, whose brother Iffy was a striker for nine professional clubs and later managed the Ethiopia national team, has a masters degree in ethnic studies and race relations and has lectured extensively on issues of race and sport. His analysis is that Taylor is unlikely to be the first England manager to have been given these instructions in the past.

“Moran’s revelation reveals that the FA’s primary concern was to preserve a predominantly white image of the England team, an image that they themselves had constructed and took great steps to preserve,” the author writes.

“There is no question of Taylor having acted on those instructions, but the episode raises some important questions as to how many other England managers were given the same instructions and therefore felt pressurised to limit the numbers of black players selected to play for the national side.

“During his playing career, Paul Davis had wondered whether some kind of unofficial quota system was in operation, but had never considered it beyond mere speculation. It would raise the question of how many black players had had their chances of playing for England restricted and what impact this might have had on England’s fortunes.”