In order to 'protect women's sport', transgender athletes 'with a male sex advantage' cannot take part in female competitions, according to ex-olympic swimmer Sharron Davies.
The two-time Commonwealth Games gold medallist said she knows 'many other female athletes who feel the same way'.
Speaking to BBC Sport, Davies, 56, said 'it is not a transphobic thing.'
The news comes as 18-time tennis Grand Slam tennis singles champion Martina Navratilova apologised for comments described as transphobic by one campaign group.
She said that male athletes 'self identifying' as female to compete is unfair and even went as far as to say it is 'cheating'.
Davies is the latest high profile name to give her opinion on the divisive issue.
'Every single woman athlete I've spoken to, and I have spoken to many, all of my friends in international sports, understand and feel the same way as me,' she told the BBC.
'Unfortunately, a lot of people who are in the races [now] are in a very difficult predicament when they can't speak out.
'It maybe falls to the people who were competing [in the past] who would understand the predicament that is being faced at the moment to try to create a debate, and try to explain how we feel there needs to be a fair and level playing field.'
Davies called for a defined set of rules that 'everybody agrees with'.
Her comments come after she posted a tweet on the issue on Friday.
She said: 'Have nothing against anyone who wishes to be transgender. However I believe there is a fundamental difference between the binary sex u r born with & the gender u may identify as.
'To protect women's sport those with a male sex advantage should not be able to compete in women's sport.'
The tweet was met with a mixed reaction. As were Martina Navratilova's comments for which she has now apologized.
The tennis legend, who is gay, is a long-term campaigner for LGBT rights but claimed that male athletes 'self identifying' as female to compete is unfair.
She was called out by Canadian academic and cycling champion Dr Rachel McKinnon, who is the first transgender woman to win a female world cycling title.
McKinnon, 35, still has her male anatomy, but has lived as a woman since she was 29.
She accused Navratilova of transphobia and demanded an apology.
Following an article on the subject that Navratilova wrote for The Times Athlete Ally, an LGBTQ athlete advocacy group, removed her from their advisory board, stating her comments 'are transphobic [and] based on a false understanding of science and data.'
Writing on her website, the 62-year-old admitted she 'stumbled into a hornet's nest' when giving her opinion on the issue.
'I know that my use of the word 'cheat' caused particular offence among the transgender community. I'm sorry for that because I certainly was not suggesting that transgender athletes in general are cheats,' she wrote.
She said her comments related 'to a notional case in which someone cynically changes gender' to gain an advantage.
The Czech-born former star said there is no 'blanket rule' that will appeal to everyone, adding: 'After all, if everyone were included, women's sports as we know them would cease to exist.'
The two-time Commonwealth Games gold medallist said she knows 'many other female athletes who feel the same way'.
Speaking to BBC Sport, Davies, 56, said 'it is not a transphobic thing.'
The news comes as 18-time tennis Grand Slam tennis singles champion Martina Navratilova apologised for comments described as transphobic by one campaign group.
She said that male athletes 'self identifying' as female to compete is unfair and even went as far as to say it is 'cheating'.
Davies is the latest high profile name to give her opinion on the divisive issue.
'Every single woman athlete I've spoken to, and I have spoken to many, all of my friends in international sports, understand and feel the same way as me,' she told the BBC.
'Unfortunately, a lot of people who are in the races [now] are in a very difficult predicament when they can't speak out.
'It maybe falls to the people who were competing [in the past] who would understand the predicament that is being faced at the moment to try to create a debate, and try to explain how we feel there needs to be a fair and level playing field.'
Davies called for a defined set of rules that 'everybody agrees with'.
Her comments come after she posted a tweet on the issue on Friday.
She said: 'Have nothing against anyone who wishes to be transgender. However I believe there is a fundamental difference between the binary sex u r born with & the gender u may identify as.
'To protect women's sport those with a male sex advantage should not be able to compete in women's sport.'
The tweet was met with a mixed reaction. As were Martina Navratilova's comments for which she has now apologized.
The tennis legend, who is gay, is a long-term campaigner for LGBT rights but claimed that male athletes 'self identifying' as female to compete is unfair.
She was called out by Canadian academic and cycling champion Dr Rachel McKinnon, who is the first transgender woman to win a female world cycling title.
McKinnon, 35, still has her male anatomy, but has lived as a woman since she was 29.
She accused Navratilova of transphobia and demanded an apology.
Following an article on the subject that Navratilova wrote for The Times Athlete Ally, an LGBTQ athlete advocacy group, removed her from their advisory board, stating her comments 'are transphobic [and] based on a false understanding of science and data.'
Writing on her website, the 62-year-old admitted she 'stumbled into a hornet's nest' when giving her opinion on the issue.
'I know that my use of the word 'cheat' caused particular offence among the transgender community. I'm sorry for that because I certainly was not suggesting that transgender athletes in general are cheats,' she wrote.
She said her comments related 'to a notional case in which someone cynically changes gender' to gain an advantage.
The Czech-born former star said there is no 'blanket rule' that will appeal to everyone, adding: 'After all, if everyone were included, women's sports as we know them would cease to exist.'
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