Hubbard is from New Zealand and competed in men's weightlifting competitions before transitioning in 2013. She has not yet qualified for the Tokyo Games, but her country's team has said she meets the current regulations of the International Weightlifting Federation.
Lambrechs told TVNZ on Thursday, (May 6) "I've had female weightlifters come up to me and say, 'What do we do? This isn’t fair, what do we do?' Unfortunately, there's nothing we can do because every time we voice it we get told to be quiet."
"I'm quite disappointed, quite disappointed for the female athlete who will lose out on that spot," she said.
Australia's weightlifting federation lobbied unsuccessfully to block Hubbard from a competition there in 2018.
In a statement on Thursday, the IOC said that while committed to inclusion, it was currently reviewing its guidelines to take into account the "perceived tension between fairness/safety and inclusion/non-discrimination".