In a statement the athlete wrote after the incident, and which was subsequently forwarded on to staff at the governing body, she said the coach had acted "inappropriately", and offered her alcoholic drinks.
In further documents obtained by the BBC, the coach also wrote separately to both the athlete and a then team manager to apologise for his "totally unacceptable" and "not appropriate" behaviour.
However, the former team manager was then told the matter was closed after the athlete requested no further action be taken.
The team manager subsequently resigned, explaining at the time in private correspondence that "pressure was being put on me to be quiet about this incident and if I were to remain in my post the people above me would not allow me to follow up on my concerns".
The athlete has now told BBC Sport: "I didn't go through with a complaint at the time because I was put in a position where it was implied by staff that I didn't want to be the one to lose the coach his job and that I was new to the programme, and I didn't want to risk that either.
"I was worried I would lose my funding and position on the programme, but that should never have been the case. I should have felt like I could trust the staff to help me work through that time, not threaten me.
"They told me that if I dropped my complaint they would discipline the coach appropriately themselves. That was something they said to try to ease me I think.
"I'm doing what I should have done a few years ago and I am not afraid of them now."
The former team manager told the BBC he believed there had been a "cover-up", adding: "I feel that the incident was mishandled by AGB from the very moment that it was reported back to them, and that procedures that they had in place, which would normally be applied in these circumstances, were circumvented.
"I think that the incident was covered up firstly out of some sort of misguided loyalty towards [the coach concerned], but mostly to protect the reputation of AGB's staff and a fear of losing funding from their sponsors. I also believe that once they had made the decision...they were locked into a spiral of deceit they had to maintain in order to protect their own positions."