Singapore is considering stopping the publication of free telephone directories listing residential and office numbers as privacy concerns mount, a government agency said.

The use of telephone directories "have declined significantly over the years", said the Infocomm Development Authority of Singapore (IDA) in a consultation paper seen by AFP on Thursday.

"In addition to the trend of declining usage of Directory Services, IDA has also observed increasing public awareness, and concerns, about use and protection of personal data," the regulatory body said.

Its review follows a personal data protection law – passed by the Singapore parliament earlier this month – which imposes heavy fines on firms making unsolicited telemarketing calls or text messages to consumers who refuse to be contacted.

"Taking into account the current landscape... IDA has considered whether it is still necessary to maintain the regulatory requirement for Directory Services," said the paper.

The IDA consultation was published on its website to solicit public feedback about the directories, which are issued in book form as well as on CDs.

Under the new law, phone users can choose to add their numbers to a "Do Not Call" registry and telemarketers are subject to a Sg$10,000 (US$8,185) fine per violation.

IDA said it had over the past year received complaints and inquiries regarding the right of telecom operators to disclose subscriber information via its telephone directories.