Japanese gaming giant Nintendo has admitted that hackers have breached 300,000 accounts since early April, gaining access to personal information such as birthdays and email addresses but not credit-card details.

An initial hack in April compromised 160,000 accounts and a further 140,000 breaches have been discovered since then, the Kyoto-based firm said in a statement released late Tuesday.

"We deeply apologise for causing trouble and worries to customers," Nintendo said in its statement, pledging to "enhance security... to prevent this happening again."

Nintendo
A Nintendo logo is pictured. AFP / Behrouz MEHRI

Hackers broke into Nintendo Network IDs, intended for services on the Wii U and Nintendo 3DS, and then migrated to Nintendo Accounts, which can be used for purchases at the company's official online store.

Fraudulent purchases from hacked Nintendo Accounts represented only a fraction of total sales, the company said, and it vowed to reimburse victims if it had not already done so.

Nintendo has been enjoying a strong showing from its popular Switch console and blockbuster games including "Animal Crossing", with demand fuelled by players stuck at home because of the coronavirus pandemic.