Swimming’s international governing body has ruled that biological males can only participate in women’s competitions if they completed their gender transition as children.

FINA announced on Sunday the move to restrict trans participation in women’s competitions for male athletes who went through puberty due to the physiological advantages males acquire during their development.

The changes, however, will still allow for female-to-male transgender athletes to compete in the men’s category.

The organization’s President Husain Al-Musallam said FINA is leading the way for preserving fairness of competition in women’s sports.

“We have to protect the rights of our athletes to compete, but we also have to protect competitive fairness at our events, especially the women’s category at FINA competitions,” he said.

British Olympic medalist Sharron Davies praised the move, saying she is proud of FINA for being “the first to be brave enough to stand up for female athletes.”

“This is a very good move and I hope now that all the other associations pick it up,” she said.

The organisation also announced that it would establish an ‘open category’ to accommodate transgender athletes who ‘transitioned’ later in life, such as Lia Thomas.

Thomas became the first transgender NCAA champion in Division I history after winning the women’s 500-yard freestyle earlier this year.

The new rules come into effect today.