International Olympic Committee (IOC) guidance on transgender inclusion poses a risk to the integrity of female competition, according to a study produced by 38 medical experts.
A new IOC framework released in November says it should not be assumed a transgender athlete automatically has an unfair advantage in female events.
The framework, which replaced IOC guidelines issued in 2015, also took out the requirement for transgender women to suppress testosterone levels to participate in those events.
However, a paper published in the "Open Sport and Exercise Medicine" medical journal said that guidance is "drafted mainly from a human rights perspective, with less consideration for medical/scientific issues".
The IOC struggled to establish a uniform position after a two-year consultation with over 250 participants, instead passing rules on to individual sports' governing federations.
Among the signatories to the report are the head of World Athletics' medical department, the medical director of cycling's ruling body the UCI and the chair of World Rowing's medicine commission.
And they question why the IOC has passed on responsibility to individual federations who will not have the capacity to implement such a framework.
Among the recommendations of the report are for the IOC to "take the responsibility to set standards and expectations based on competitive fairness and the best available science that all International Federations can follow".
A report by Britain's Sports Councils Equality Group (SCEG) in September concluded the inclusion of transgender people, fairness and safety "cannot co-exist in a single competitive model" for many sports.