Cyber hackers calling themselves Fancy Bears published a new batch of documents on Wednesday on their website containing "confidential athlete data of 25 athletes, from eight countries, into the public domain".
Among those athletes are 14 medal winners at the 2016 Summer Olympic Games in Rio de Janeiro.
There is no suggestion the British athletes are involved in any wrongdoing, according to a BBC report.
WADA said on Wednesday the cyber attack is an attempt to undermine the global anti-doping system and claimed that Russian hackers were behind the cyber attacks.
The records released by the group calling itself Fancy Bears mostly detail "Therapeutic Use Exemptions" (TUEs) allowing banned substances to be taken for athletes' verified medical needs.
The group says the TUEs are "licenses for doping" and that WADA is "corrupt and deceitful".
WADA Director General Olivier Niggli, strongly criticised the leak.
"WADA is very mindful that this criminal attack, which to date has recklessly exposed personal data of 29 athletes, will be very distressing for the athletes that have been targeted and cause apprehension for all athletes that were involved in the Rio 2016 Olympic Games," he said on Wednesday.
Niggli said there was "no doubt" that the hack was retaliation against WADA for its report on Russian state-sponsored cheating and appealed to the Russian government to help stop it.
The Russian authorities have denied any involvement.
The first batch of documents was published by the hacker group on Tuesday, containing personal data of four American athletes - gymnast Simone Biles, tennis players Serena and Venus Willians and basketball player Elena Delle Donne.
