Allen was speaking in the wake of numerous allegations of abuse in recent weeks from high-profile British gymnasts, including sisters Becky and Ellie Downie, and Olympic bronze medallists Amy Tinkler and Nile Wilson.

The governing body has already commissioned an independent review into the series of allegations.

In a column for The Telegraph Allen wrote: "When stories of mistreatment in gymnastics first appeared in the media five weeks ago, I was appalled and ashamed.

"Over the past 10 years we have worked hard and invested significant resources to strengthen our safeguarding and complaints team which today stands as an Integrity Unit of 12 people with responsibility to impartially investigate allegations of abuse, bullying, unfair treatment and failures to comply with our rules. 

"While our safeguarding systems, processes and staff performance have been audited, accredited and championed by leading experts in the field, we clearly must do more.

"Complaints that have been heard and judged by independent experts are being questioned by gymnasts who believe they have not been 'backed' by the system. 

"Some complaints made through the media in recent weeks have never been seen by our Integrity Unit.

"The last five years have seen an average of 300 reports per annum made to the Integrity Unit, ranging from allegations of poor practice and rule-breaking to more serious claims of misconduct and abuse. 

"Recent events demonstrate that barriers to complaints exist and change is needed to restore confidence in the fairness of the process. 

"We must work harder to explain the importance of a system that protects integrity for all parties involved. 

"At present that is not the case, with emerging concerns of bias against gymnasts."

The independent review into British Gymnastics is being overseen by UK Sport and Sport England.

Allen has temporarily stood down from her role as a member of UK Sport's major events panel while the review is being conducted, in order to "remove any suggestions of a conflict of interest."

"We have tried to do our best to protect our members and while we have succeeded in many cases, in others we have fallen short," said Allen.

"Athletes and coaches will often feel aggrieved if the process does not find in their interests and worry that the system is against them. 

"We must find new ways to explain why decisions have been made. 

"At present, the mistrust from those judged against leads to a vicious cycle that threatens the entire process."

Gymnastics New Zealand and the Royal Dutch Gymnastics Union have announced similar independent review processes in recent weeks. 

Allen added that British Gymnastics supported multiple Paralympic athletics champion Dame Tanni Grey-Thompson's calls for the creation of a Sports Ombudsman to hold governing bodies to account and provide a higher level of review for controversial cases.

Allen said the creation of a Sports Ombudsman would protect "athletes, coaches and individual sports."