Login IDs and passwords of Tokyo Olympic ticket purchasers have been leaked on the internet, a government official said Wednesday, in the latest in a series of setbacks for the organizing committee.

The same information of Paralympic ticket purchasers and those who had used a volunteer portal for the Summer Games have been leaked online as well, said the official, speaking on condition of anonymity, adding that the organizing body has launched an investigation into the matter.

Disclosure of the leakage came as Japanese musician Keigo Oyamada resigned this week from the team producing Friday's opening ceremony of the Olympics after admitting to bullying and abusing children with disabilities in the past, while organizers have already been struggling to turn public opinion in their favor amid the coronavirus pandemic.

According to the official, the scale of the leakage is "not large," and measures have already been taken to prevent a further spread of such information.

The usernames and passwords used to log in to websites for the games' volunteers and ticket purchasers were likely stolen by unauthorized access to computers or smartphones, and they were posted on a website that exposes personal information, the official said.

If a login ID and password are used, it may be possible to access more personal data of a purchaser or a volunteer, including the name, address and a registered bank account.