Female transgender riders who transitioned after male puberty will be prohibited from women's events in all categories of cycling, the sport's governing body said on Friday.
The International Cycling Union (UCI)'s president David Lappartient said the federation "has a duty to guarantee, above all, equal opportunities for all competitors in cycling competitions".
The new rules, which come into force on July 17, follow similar rulings by other Olympic sports such as athletics and swimming.
"The UCI would like to reaffirm that cycling – as a competitive sport, leisure activity or means of transport – is open to everyone," Lappartient said in a statement.
But the current state of scientific knowledge does not guarantee such equality of opportunity between transgender female athletes and cisgender female participants, he added.
"As a precautionary measure, (it is not possible to) authorise the former to race in the female categories," Lappartient added.
The UCI said anyone who has transitioned after male puberty could compete in a "men/open" category.
The UCI said it was open to changing these rulings in the future as scientific knowledge evolves.
The UCI said it will begin discussions with other members of the international sporting movement on the co-financing of a research programme aimed at studying changes in the physical performance of highly-trained athletes undergoing transitional hormone treatment.
Last year top British women's cyclists threatened to boycott events after 22-year-old Emily Bridges, who was dropped by the British academy programme as a male rider, attempted to join the women's omnium team.
But it was the victory of female American transgender cyclist Austin Killips in a UCI women's event two months ago that prompted the governing body to reopen consultation on the issue.
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