A gymnastics coach who quit the Australian Olympic team after the ABC revealed he allegedly harassed a former colleague is now being accused of making sexual comments to former teenage athletes, including nicknaming their bottoms.

The allegations against Jeb Silsbury, who currently trains an Olympian at the Cheltenham Youth Club in Melbourne's south-eastern suburbs, come from his time coaching at the MLC Gymnastics Club, which is attached to the Methodist Ladies' College — a prestigious girls' school in Melbourne.

An ABC investigation has uncovered allegations from two former MLC gymnasts, one of whom alleged that Mr Silsbury's behaviour "went on for years" and involved sexually explicit comments.

The allegations were reported to the school and Mr Silsbury was fired.

Mr Silsbury did not respond to multiple requests for comment.

Alleged inappropriate comments left girl feeling 'embarrassed'

One former gymnast, now 29, said that when Mr Silsbury arrived at MLC Gymnastics in 2008, he was friendly.

She said when the team travelled overseas for international competitions, he would drop off chocolates to the athletes' rooms or buy them gifts like T-shirts or treats from the airport.

But she alleged that as time went on, Mr Silsbury's comments became progressively more inappropriate. 

She recalled Mr Silsbury allegedly describing some gymnastics skills as "like the best orgasm ever" or "like good sex".

The gymnast said that some strength exercises, such as hip thrusts, also attracted sexually explicit comments.

"He used to say, 'just pretend so-and-so is laying on top of you'," she claimed.

"I never used to do that exercise when he was around because I was so embarrassed."

Gymnast alleges coach made comments about her body

The gymnast claimed Mr Silsbury would sometimes comment on his athletes' bodies, including hers, and went as far as nicknaming their body parts.

"I remember him telling me I had a rounder bum than everyone else," she said.

"How are you supposed to respond? So we used to just hysterically laugh at it and then that became a coping mechanism."

She said the incident had had a lasting impact on her.

"For years after … I'd wear really long and baggy T-shirts because I was so embarrassed," she said.

"I was young and I wanted to do gymnastics and I kind of just ignored it.

"I think I turned a blind eye to a lot of what he was doing."

Another gymnast, who is now 28, alleged Mr Silsbury also made sexual comments while he was coaching her.

"He would make some inappropriate comments like for example … the Rihanna song S&M was playing once … he'd just say 'sex smells funky'," she said.

"I just think it's weird that he said that to a group of underage girls … he was our coach, that's inappropriate, considering the professional kind of role he should've been playing."

She said that on some other occasions Mr Silsbury allegedly leered at her.

"You're wearing a leotard, there's not a lot of cover there," she said.

"I just would always feel real uncomfortable."

Mother recalls 'sickening feeling' after daughter shared allegations

Coaches are expected to abide by Gymnastics Australia's member protection policy, which sets guidelines for behaviour within the sport.

Coaches are told to avoid language that is inappropriate or "profane or sexual".

Things came to a head for the now 29-year-old in 2012, when she told her adult sister about Mr Silsbury texting her.

She said the texts were friendly, but it raised alarm bells with her family members.

Her sister recalled the conversation to the ABC.

"I don't think she fully had a grasp of what was happening properly, like the seriousness of it," the sister said.

"Initially I think she didn't want to share how much she was perhaps being texted.

"I think she felt conflicted, I don't think she knew how to deal with it.

"I sensed she felt a bit trapped."

At her sister's encouragement, the gymnast told her mother about Mr Silsbury's alleged behaviour while they were on the way to a training session.

"You have a sickening feeling, you know … as if you don't want to have that information in your head," her mother recalled.

"I felt like, 'I have to tell someone'," she said.

Employment terminated after parent raised concerns

The gymnast's mother approached Mr Silsbury's boss, Michelle De Highden, MLC Gymnastics Club's head coach and high performance manager, and a meeting was scheduled at the school.

The gymnast recalled Ms De Highden taking notes during the meeting, as she sat with her mother.

"It kind of looked like her heart was sinking, she looked distressed," the gymnast said.

"She did hug me at one point and said it wasn't my fault."

Ms De Highden now works at the Australian Institute of Sport (AIS), which is managed by the Australian Sports Commission.

A spokesman for the commission said Ms De Highden reported the alleged concerns about Mr Silsbury to MLC's human resources department.

"MLC Gymnastics Club subsequently made the decision to terminate Mr Silsbury's employment," a spokesman said.

"The accounts shared by athletes are concerning and there is no place for behaviours like this in Australian sport.

"Ms De Highden was informally approached by Mr Silsbury's next employer and she did not recommend him for employment."

The current principal of Methodist Ladies' College Julia Shea, who was not at the school during that period, confirmed "a concern was reviewed and addressed promptly" during Mr Silsbury's time at MLC.

"Following an investigation, appropriate actions were taken in accordance with our policy and standards of the time," the principal said.

"We can assure you that MLC's decision-making at the relevant time was, at all times, guided by the prevailing mandatory reporting and child safety practices, as in place at the time," she said.

The 29-year-old former gymnast said she later found out Mr Silsbury had taken a job at Waverley Gymnastics, which she said caused her angst.

"I think Gymnastics Australia has a lot to say for itself and I don't think I would ever put my child in gymnastics if it remains like this because I can't trust the coaches and the way that they treat their gymnasts," she said.

Gymnastics Australia says allegations are 'concerning'

In July, Mr Silsbury withdrew from the Olympic Games the day before the national team was due to fly to Paris after the ABC alerted the Australian Olympic Committee to a former colleague's allegations of inappropriate behaviour.

An ABC investigation revealed Gymnastics Australia was aware of a serious complaint of inappropriate behaviour against Mr Silsbury before he was selected for the Australian Olympic team.

The ABC now understands that Gymnastics Australia had previously limited Mr Silsbury's involvement in national camps over concerns about his past behaviours.

Gymnastics Australia said the allegations against Mr Silsbury were "concerning".

"Any inappropriate behaviour is unacceptable and has no place in our sport," a spokeswoman said.

"We encourage anyone with concerns to submit a Formal Complaint or Report through Sport Integrity Australia.

"Every coach and judge registered with Gymnastics Australia is required to undertake mandatory annual safeguarding training, and to uphold our national codes of conduct. 

"Any behaviours or actions that are found to be in breach of our standards, policies or procedures are taken seriously and will be addressed."

The ABC understands Gymnastics Australia will not investigate the allegations against Mr Silsbury, who is free to continue coaching, because there has not been a formal complaint against him.