USA Gymnastics is reportedly investigating coach Maggie Haney over allegations of emotional and verbal abuse of athletes.
According to the Orange County Register, Haney has also been accused of pressuring athletes to compete while injured.
The Californian daily newspaper reported Haney, who coached 2016 Olympic team gold medallist Laurie Hernandez, has been accused of persistent verbal and emotional abuse.
She allegedly screamed, threatened, bullied and harassed American gymnasts.
Haney now coaches Riley McCusker, a member of the American squad which claimed the team title at the 2018 World Championships in Doha and won two gold medals at the Pan American Games in Lima.
The Register reported there had been at least four complaints from families regarding Haney's behaviour and conduct.
USA Gymnastics declined to comment directly, but said in a statement that "all misconduct reports and concerns are taken very seriously and handled proactively".
"Thoroughly reviewing, evaluating and investigating a safe-sport report is vital, which means it is not necessarily a quick process," USA Gymnastics said.
"While it may appear to the outside that a report or matter is on hold or ignored, the truth is that the report/matter is being dealt with confidentially in accordance with the established process and procedures, which fully comply with federal law and United States Olympic and Paralympic Committee requirements.
"USA Gymnastics only comments on a safe-sport matter if and when the resolution involves a public-facing result, such as being added to the list of individuals on the suspension/restrictions or permanently ineligible for membership lists, or if a panel’s decision yields a public-facing result."