SINGAPORE - Troubled karaoke bar chain K Box, which suffered one of the biggest data breaches here, said that it has removed 80 per cent of the links leading to its leaked members' data.

"We are continuing our efforts to ensure that all of such Internet links are removed," said K Box in a statement on Friday evening.

The personal data of over 300,000 customers were exposed, with the firm possibly facing sanctions for lax security. Their names, addresses and mobile phone and identity card numbers were posted on several websites on Tuesday, purportedly by hackers protesting against upcoming toll fee hikes at Woodlands Checkpoint.

The leak of K Box's membership database is being investigated by privacy watchdog, the Personal Data Protection Commission.

The commission said that organisations must take "reasonable measures" to protect personal data in their possession under privacy laws which came into force on July 2. Companies found in breach of the law face fines of up to $1 million.