Lin has won two golds medals at World Championships but has not contested an Olympic final, having lost in the last 16 to Petecio at the Tokyo Games.
At last year’s World Championships, Lin reached the semi-finals – thus securing a bronze medal – but was disqualified by the IBA.
The IBA said Lin had “failed to meet the eligibility criteria for participating in the women’s competition, as set and laid out” in its regulations.
But Lin and Algerian Khelif, who was disqualified from the same tournament, have been allowed to compete at the Olympics, which is run by the International Olympic Committee (IOC).
The IOC, which suspended the IBA in 2019 because of concerns over its finances, governance, ethics, refereeing and judging, has strongly backed Lin and Khelif, with president Thomas Bach saying there was “never any doubt” they are women.
The organisation said competitors were eligible for the women’s division if their passports said they were female, and a a chaotic news conference held on Monday did little to lessen the confusion around the IBA’s stance as key figures gave conflicting statements as to why the pair were banned.
Khelif fights Liu Yang of China for gold on Friday at 21:51 BST. Lin’s bout will open the final night of boxing at the Paris Olympics at 20:30 on Saturday.