KUALA LUMPUR - Malaysian authorities investigating a massive online data breach involving 46 million mobile phone users have now widened their search to another two countries - Netherlands and Hong Kong, said the national police chief on Sunday (Dec 3).

"There were supposedly three e-mails used to spread the information, each using an IP (Internet protocol) address from Oman, Netherlands, and Hong Kong.

"We are trying to identify the owner of these accounts and this represents our current challenge in conducting investigations," said Tan Sri Mohd Fuzi Harun at an event on Sunday, reported the Malay Mail Online.

Police had in November revealed that the leak was traced to an IP address in Oman.

They are investigating the data breach with the Malaysian Communications and Multimedia Commission (MCMC).

Mr Mohd Fuzi added that it was not yet necessary to seek the assistance of other countries in the probe. He also said it was still unknown if an individual or a syndicate was responsible for the incident.

News of the data breach first surfaced on Lowyat.net in October, when the technology news site reported that some 46.2 million cellular service accounts of Malaysian telcos and mobile virtual network operators (MVNO) had been compromised and leaked online.

The site said the leak, believed to have taken place between 2014 and 2015, included postpaid and prepaid numbers, customer addresses as well as SIM card details from major telcos in the country including DiGi, Celcom, Maxis, Tunetalk, Redtone and Altel.

No arrests have been made so far.