“Had we been aware, or had this been declared at any point before or during the competition, this athlete would not have been permitted to compete in the Woman’s Open category,” the statement added.
“It is our responsibility to ensure fairness and ensure athletes are assigned to men or women’s categories based on whether they are recorded as male or female at birth.”
Thompson, first crowned world’s strongest woman in 2018, said the manner she had won the title had taken the gloss off it, but praised Strongman for “investigating and rectifying the situation so quickly”.
“What should be a momentous occasion has sadly been overshadowed by scandal and dishonesty from someone who was welcomed into our crazy sport,” she said in a post on her Instagram, external account.
“I am not only frustrated with not being able to celebrate a win, but also for the ladies who had their time to shine on the podium or reach the final day, taken away from them.”
Thompson, from Suffolk, said she and fellow competitors were “mentally drained” having “received backlash and insults” since the decision, which “needs to stop”.
“This has been the most exhausting experience of my career,” she added.
“We, as a community are taking a stand. Protecting women’s sport as we have fought so hard for.”