Florida governor Ron DeSantis has signed a proclamation recognising runner-up Emma Weyant as the winner of the highest US national college swimming title – an event she lost to transgender athlete Lia Thomas.

She took victory in the women’s 500-yard freestyle in Atlanta.

But on Tuesday Republican governor DeSantis said the result “undermined the integrity of the competition”.

Thomas, who swims for the University of Pennsylvania, secured the title in four minutes 33.24 seconds in Atlanta.

Weyant, of Sarasota, Florida, who won 400m individual medley silver at the Tokyo Olympics, finished 1.75secs behind in second.

DeSantis criticised the National Collegiate Athletic Association (NCAA) for allowing Thomas to compete.

He said: “The NCAA is basically taking efforts to destroy women’s athletics, they’re trying to undermine the integrity of the competition and they’re crowning somebody else the women’s champion and we think that’s wrong.

“They are putting ideology ahead of opportunity for women athletes and I think that there are just some people that are afraid to speak out and say what they are doing, but that is what they are doing.”

Thomas swam for the Pennsylvanian men’s team for three seasons before starting hormone replacement therapy in spring 2019.

US swimming updated its policy in February to allow transgender athletes to swim in elite events, alongside criteria that aims to reduce any unfair advantage.

The NCAA – which governs college-level swimming – ruled it would be wrong to implement the new rules mid-season, thus allowing Thomas to compete.

On Monday World Athletics president Lord Coe issued a warning over the future of women’s sport if sporting organisations get regulations for transgender athletes wrong.

“I think that the integrity of women’s sport if we don’t get this right, and actually the future of women’s sport, is very fragile,” Coe said.