The governing body's Council now rules that only rowers who are identified as female at birth and did not transition to another gender by the time they reached puberty are eligible to compete as a woman.

All other rowers must race in men's events.

Previously, rowers were allowed to compete in the gender show on their passport.

Those competing in women's categories also had to maintain a continuous serum testosterone level of five nanomoles per litre for at least 12 consecutive months prior to an event.

Now that has been reduced to 2.5nmol/L for 24 straight months.

World Rowing claims that the review was based on scientific evidence highlighting performance differences between men and women, and the changes have been made with "the core objective of guaranteeing fair competition and participation for women in the sport.

"The matter presented is not solely a scientific question but involves ethical, social, cultural and legal aspects," read a World Rowing statement.

"Members of the rowing community hold views as a matter of sincerely held principle at both ends of the spectrum, from those who believe that competitive classification should be determined solely by the gender identity as expressed by the athlete, to those who believe that classification should be based solely on biological sex as determined at birth.

"Our precept regarding transgender athletes requires reconciliation of principles of inclusion and non-discrimination on the one hand, and also fairness to all competitors and the protection of women's sports on the other.

"These principles sometimes are in tension, and some will say, are in irreconcilable conflict."

The Executive Committee relied on the evaluation of an independent body named the Gender Advisory Panel for the decision.

It sees a change to the existing Bye-Law to Rule 13.

Although World Rowing Statutes may only be altered by the Quadrennial Congress, which is held after the Summer Olympic and Paralympic Games , changes to the Bye-Laws can be approved by the Council every year.