Now the 37-year-old retired athlete has told everyone about the attempted rape she managed, eventually, to fend off as part of an absorbing account of her tumultuous career in the newly published My Hidden Race.

The excruciating detail for Onuora is that the drunken "sportsman" whom she describes forcing his way into her room and then forcing himself upon her was known to her and she had to meet him on subsequent occasions in her career.

But she adds: "After years of sacrifice and pain, I had finally achieved a level of success and I didn't want this sickening episode to define my career."

Shortly before seizing her fleeting chance of kicking her way free of her attacker, Onuora recalled saying to herself: "Just keep fighting with everything, Anyika. Fight him. Fight. Fight. Fight."

Those words could just as easily refer to her attitude throughout her career as she emerged as an unwilling but natural athletic talent in Liverpool, where she and her family endured sustained racial abuse, and battled her way to the sport's major podiums.

The details of that hotel attack are harrowing. But what tells just as sharply throughout the book are the details of racism that Onuora, whose parents moved to the UK from Nigeria, has endured ever since she can remember.

While her initial memories of living in Wavertree are largely warm ones, she recounts how, after the family moved to Liverpool's Dingle suburb, she was regularly abused by local gangs, called names and spat on.

"The front of the house became an absolute no-go zone due to the front window being shattered most nights," Onuora writes.

"So we existed in the relatively well-protected back rooms. Mum and Dad were increasingly tense and worried but still did their very best to protect us as best they could by assuring us that everything was going to be okay."

On Sundays, when the family would attend church, the house was often burgled and attacked. On one occasion their car was destroyed after being set alight. They did not bother to report it to the police.

One local couple, Carol and Jimmy, were regularly in touch. "The kindness of this family and other neighbours kept us going," Onuora adds.

While life became more bearable when the family, fearful of their safety, moved back to Wavertree, racial prejudice would continue to be a part of Onuora's experience.

Even after she had established herself as one of Britain's leading athletes, she was still fighting battles on that front. The year after she had been part of the British team that won 4x400 metres bronze at the 2015 Beijing World Championships, she returned to training at the High Performance Centre in Loughborough.

"I noticed that they had decided to brand the Centre with posters of celebrated British athletes that could inspire the next generation to hopefully follow in their footsteps," she writes. "I also noticed that there wasn't a single black British female athlete on the walls."

With the help of former sprinter Paula Dunn, "the only black representative at senior management level", she arranged a meeting that she describes as "formal and sombre….not a success". As things turned out she was wrong - a selection of black British female athletes was added, albeit after more than a year of waiting.

"It was never about posters," she reflects. "It was about a bigger picture of not feeling valued by the organisation."

Soon after raising the matter of the posters, Onuora was involved in what proved to be the high point of her career in what was her most successful season. It was all the more remarkable for the fact that, soon after the Beijing 2015 World Championships, she had caught a severe strain of malaria while visiting family in Nigeria and came very close to dying.

Having confounded medical opinion by recovering her athletic career, Onuora was part of the 4x400m team that won gold at the 2016 European Championships in Amsterdam and went on to the Rio 2016 Olympics with high ambitions.

While waiting, with nerves at full stretch, in the stadium holding room before the final, Onuora overheard "the words of a senior UK Athletics figure".

"I hope these girls are f*****g ready. There's 10 million quid in funding on the line if they don't get a medal. I'm telling you, they better f*****g get this together tonight."

Onuora adds: "I wasn't meant to hear those words. I heard them as I was in the team huddle before we went out onto the track and they have successfully turned my anxiety levels up a notch.

"The official talked about us as if we are an unpredictable index fund on the London Stock Exchange, not four women who have sacrificed everything to be at the Olympics."

Onuora's preparations for Rio 2016 had been peculiarly vexed. Having managed only third place at the British trials, she found herself in what was billed as a race-off for the last individual place at the Amsterdam European Championships - against former world and Olympic champion Christine Ohuruogu, her dear and longstanding friend whom she regarded "as a sister". Awkward.

Onuora beat Ohuruogu to the individual 400m bronze. "Christine comes over and softly says 'you ran a great race, congratulations,'" she writes. "It meant everything to hear her say that."

When the UK Athletics selectors decided nevertheless to choose Ohuruogu, Onuora launched an appeal that proved unsuccessful.

In the Rio 2016 final, with the Jamaican and United States teams contesting gold, Onuora took the baton from Eilidh Doyle, passed it to Emily Diamond, who then passed it to Ohuruogu who serenely defended the bronze medal position.

After a joyful lap of honour, the British quartet received hugs from Stephen Maguire, head of the sprint relay programme, and performance director Neil Black.

"This race wasn't just about four women winning an Olympic medal, it has saved the collective asses of UK Athletics officialdom. They have hit their targets and their hugs are filled with sheer relief," Onuora writes.

Finally, however, she is able to reflect upon the feeling of having an Olympic medal.

"It's a funny feeling, almost like getting the Christmas present that you had always wanted, and now it's finally unwrapped and yours to keep forever," she said.

"So many times I had asked myself why I continued in this sport. Finally I knew why."