Transgender ban

It would be the first international sports federation to prohibit transgender women from competing.

World Rugby said it had undertaken a review of its "rugby-specific transgender guidelines" in light of the "latest peer reviewed research".

It said it was committed to "ensuring a safe and inclusive playing environment at all levels of the game".

Defence Secretary Ash Carter has called the regulation outdated and harmful to the military.

The disclosure has been welcomed by campaigners for transgender rights.

It comes after the US Army Secretary, Eric Fanning, formally took office. He is the first openly gay person to become the top civilian official in any branch of the American military.

The US military ended its ban on openly gay and lesbian service personnel in 2011.